Free Online Calculator – Fast & Easy Math Tools

Perform essential math operations for daily calculations. Perfect for homework, budgeting, and quick calculations.

Free percentage calculator. Quickly find percentage increase, decrease, change, or what percent of a number another number is. Easy & accurate.

Free online square root calculator (radical calculator) to find the square root of any number. Calculate √x with precision and learn the mathematical principles behind square roots and radicals.

Calculate fillet (rounded corner) geometry from radius, chord, arc length, sagitta or angle. Visualize the arc, get sector/segment area, and export SVG. Units: mm/cm/in/px.

Calculate the area of seven common shapes: rectangle, triangle, trapezoid, circle, sector, ellipse, and parallelogram. Perfect for geometry, construction, and land measurement.

Free Triangle Area Calculator to find area using sides, base-height, angles, or coordinates. Quick, accurate, and easy tool for students and professionals.

Calculate scalene triangle area using Heron's formula with three sides. Enter side lengths for unequal-sided triangles to get exact area instantly. Perfect for geometry, engineering, and math homework.

Find triangle area using base and height with this free calculator. Quick and accurate results for geometry practice, engineering, or homework problems.

Calculate triangle area with two sides and the included angle using sine formula. Easy and accurate solution for trigonometry and geometry problems.

Compute triangle area using two angles and one side. Apply law of sines to find area quickly. Ideal for trigonometry and geometry study help.

Calculate triangle area using vertex coordinates with this free tool. Enter three points (x,y) to get exact area instantly for math or CAD work.

Free Right Triangle Area Calculator. Find area using base and height or two legs instantly. Great for math students and quick geometry checks.

Perform binary arithmetic operations with step-by-step visualization. Supports addition, subtraction with carry/borrow annotations.

Calculate 1's complement (one's complement) by flipping every bit of a binary or decimal number under a fixed bit width (8/16/32/64). View results in binary, decimal, and hexadecimal formats with bit-by-bit visualization.

Calculate 2's complement (two's complement) for representing negative numbers in binary. Convert between binary, decimal, and hexadecimal with 8/16/32/64-bit support and step-by-step visualization.

Convert binary numbers to decimal instantly. Free online binary to decimal converter with detailed steps for quick and accurate conversions.

Convert binary numbers to hexadecimal instantly. Free online binary to hex converter with detailed steps for quick and accurate conversions.

Convert binary numbers to octal instantly. Free online binary to octal converter with detailed steps for quick and accurate conversions.

Convert decimal numbers to binary instantly. Free online decimal to binary converter with detailed steps for quick and accurate conversions.

Convert decimal numbers to hexadecimal instantly. Free online decimal to hex converter with detailed steps for quick and accurate conversions.

Convert decimal numbers to octal instantly. Free online decimal to octal converter with detailed steps for quick and accurate conversions.

Convert hexadecimal numbers to binary instantly. Free online hex to binary converter with detailed steps for quick and accurate conversions.

Convert hexadecimal numbers to decimal instantly. Free online hex to decimal converter with detailed steps for quick and accurate conversions.

Convert hexadecimal numbers to octal instantly. Free online hex to octal converter with detailed steps for quick and accurate conversions.

Convert octal numbers to binary instantly. Free online octal to binary converter with detailed steps for quick and accurate conversions.

Convert octal numbers to decimal instantly. Free online octal to decimal converter with detailed steps for quick and accurate conversions.

Convert octal numbers to hexadecimal instantly. Free online octal to hex converter with detailed steps for quick and accurate conversions.

Free trigonometry calculator for sin, cos, tan, and inverse trig functions. Convert degrees/radians, explore graphs, unit circle values, and trig tables. Fast, accurate, and easy to use.

Instantly compute sin(x) in degrees or radians. Includes graph insights, common values, and quick examples.

Calculate cos(x) instantly in degrees or radians. Includes cosine properties and common angle values.

Compute tan(x) and highlight undefined positions automatically. Degree/radian support included.

Find arcsin(x) and view angle outputs in degrees or radians.

Calculate arccos(x) with full precision and domain validation.

Compute arctan(x) with rad/deg output and quadrant considerations.

Trigonometry table (0°–360°) with sin, cos, tan in degrees and radians, special-angle exact values, quadrant signs, and any-angle lookup.

Explore the unit circle interactively: angles → (x, y), sin, cos, tan.

Plot sine, cosine, and tangent functions. Adjustable amplitude and period.

Compute expressions like sin(arctan(x)), cos(arctan(x)), and tan(arcsin(x)).

Calculate arc length of a circle using radius, diameter, and angle in degrees or radians. Free online arc length calculator with step-by-step solutions and formulas.

Calculate the area of a circle using radius or diameter. Free online circle area calculator with πr² formula, unit conversion, and step-by-step solutions.

Complete circle calculator: calculate radius, diameter, circumference, and area from any one known value. Free online circle calculator with formulas and step-by-step solutions.

Calculate circle geometry theorems: inscribed angles, central angles, and tangent-chord angles. Free online circle theorems calculator with explanations and formulas.

Calculate the circumference of a circle using radius or diameter. Free online circumference calculator with C = 2πr and C = πd formulas, step-by-step solutions.

Calculate the equation of a circle in standard form (x-h)²+(y-k)²=r² and general form. Free online circle equation calculator with center, radius, and coordinate geometry.

Calculate the area of a circle sector using radius and angle in degrees or radians. Free online sector area calculator with formulas and step-by-step solutions.

Calculate the area and perimeter of a semicircle using radius or diameter. Free online semicircle calculator with formulas and step-by-step solutions.

Calculate the side length and area of a square inscribed in a circle. Free online calculator with formulas, diagonal relationships, and step-by-step solutions.

Plan your borrowing with precision. Calculate monthly payments, total interest costs, and loan affordability for any type of loan.

Convert between 150+ world currencies with real-time exchange rates. Essential for international travel, online shopping, business transactions, and investment analysis. Get accurate conversion rates updated throughout the day.

Calculate tips and split bills with friends and family. Include or exclude taxes and service charges, round amounts for convenience.

Free online Mortgage Calculator to estimate monthly payments including principal, interest, taxes, insurance, and HOA fees. Compare different down payments and loan terms to find affordable home financing.

Free Car Loan Calculator to estimate monthly payments, total interest, and payoff schedule. Adjust loan amount, rate, and term to plan your auto financing.

Free Personal Loan Calculator to estimate monthly payments, total interest, and payoff schedule. Adjust loan amount, rate, and term to plan your finances.

Free Student Loan Calculator to estimate monthly payments, total interest, and payoff date. Plan repayment strategies and compare different loan options.

Free Business Loan Calculator to estimate monthly payments, interest costs, and amortization schedule. Adjust loan amount and term to plan cash flow.

Free HELOC Calculator to estimate your home equity line of credit, monthly payments, and interest costs. Explore borrowing options and repayment terms.

Forecast SCHD dividends and total returns. Calculate DRIP reinvestment, yield on cost, and passive income growth with our simple tool.

Free online BMI calculator. Enter your height and weight to get an accurate Body Mass Index, classification, normal BMI ranges, Asian BMI option, formula, chart, and examples.

Accurate BMI calculator for women. Enter your height and weight to get your BMI, classification, women-specific healthy ranges, chart, formula, and examples.

Free BMI calculator for men. Check your BMI, healthy ranges for men, muscle-mass considerations, chart, and classification.

Child and teen BMI calculator using CDC percentiles. Enter age, sex, height, and weight to get BMI, percentile, and classification.

UK & NHS-based BMI calculator. Uses official NHS BMI ranges with clear classification, chart, formula, and healthy weight guidance.

Canada-based BMI calculator using Health Canada guidelines. Enter height and weight to get BMI, classification, healthy ranges, chart, and examples.

Australia-focused BMI calculator. Enter height and weight to get your BMI, classification, healthy range, chart, and guidance.

Calculate how long it takes to finish an audiobook at different playback speeds. Find out time saved and estimated completion date based on your daily listening habits.

Calculate the maximum audiobook length you can complete based on available time and playback speed. Perfect for planning your reading schedule and book selection.

Calculate your GPA and course grades with weighted assignments. Track academic performance and plan study strategies.

Free online Age Calculator to calculate your exact age in years, months, and days from your date of birth. Quick, accurate, and easy to use!

Free online time calculator to find the difference between two dates or add/subtract years, months, days, hours, minutes, and seconds from any date.

Calculate the exact duration between two dates and times. Free time duration calculator for precise time span calculations, travel planning, and project timelines.

Find the exact date that was 180 days ago from today in your local time. Ideal for half-year planning, probation periods, and long-term contracts. Includes weeks, approximate months, and clear calendar rules.

Calculate the exact date 120 days ago from today. Perfect for quarterly planning, long-term project tracking, and extended time period calculations.

Find the exact date for 90 days ago from today in your local time. See days, weeks, and approximate months with clear rules, quick copy, and related date tools.

Find the exact date for 60 days ago from today in your local time. See days, weeks, and approximate months with clear rules, quick copy, and related date tools.

Find the exact date that was 45 days ago from today in your local time. Ideal for 6-week projects, extended reviews, and payment windows. Includes weeks, approximate months, and clear calendar rules.

Find the exact date for 30 days ago from today in your local time. See days, weeks, and approximate months with clear rules, quick copy, and related date tools.

Find the exact date that was 21 days ago from today in your local time. Ideal for 3-week sprints, vacation planning, and 21-day challenges. Includes weeks, approximate months, and clear calendar rules.

Find the exact date that was 14 days ago from today in your local time. Ideal for bi-weekly cycles, payroll periods, and 2-week sprints. Includes weeks, approximate months, and clear calendar rules.

Find the exact date that was 7 days ago from today in your local time. Ideal for short-term planning, weekly schedules, and 7-day trial periods. Includes weeks, approximate months, and clear calendar rules.

Find the exact date that will be 7 days from today in your local time. Ideal for short-term planning, weekly schedules, and 7-day deadlines. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 14 days from today in your local time. Ideal for bi-weekly cycles, payroll periods, and 2-week deadlines. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 21 days from today in your local time. Ideal for 3-week sprints, vacation planning, and 21-day deadlines. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 30 days from today in your local time. Ideal for monthly planning, billing cycles, and 30-day deadlines. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 45 days from today in your local time. Ideal for 6-week projects, extended reviews, and payment windows. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 60 days from today in your local time. Ideal for mid-term planning, bi-monthly cycles, and extended deadlines. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 90 days from today in your local time. Ideal for quarterly planning, three-month milestones, and seasonal deadlines. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 120 days from today in your local time. Ideal for extended quarters, long-term project deadlines, and four-month planning. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the exact date that will be 180 days from today in your local time. Ideal for half-year planning, probation periods, and long-term contracts. Includes weekday, weeks, approximate months, and clear calendar rules.

Find the date 26 weeks (about half a year) ago from today. Great for HR, finance, and reporting.

Find the exact date 16 weeks ago from today. Calendar-day calculation with helpful tips.

See the exact date 12 weeks ago from today with examples and quick copy.

Quickly calculate what date was 8 weeks ago from today. Useful for schedules, finance, and planning.

Find the exact date 4 weeks ago from today. Instant answers, copyable results, business day notes, and examples.

Calculate the exact date 4 weeks from today. Instant result with examples and notes.

Find the exact date 8 weeks from today with one click.

See the exact date 12 weeks from today. Business-day notes included.

Find the exact date 16 weeks from today. Copy result instantly.

Calculate the date 26 weeks (about half a year) from today.

See exactly how many days, weeks, Mondays, and business days are left until the next Memorial Day. This Memorial Day countdown updates automatically every day.

Find out how many days, weeks, Mondays, Fridays, and business days are left until Memorial Day 2025 on May 26, 2025. Countdown updates automatically.

See how many days and weeks remain until Memorial Day 2026 on May 25, 2026. Automatically updated Memorial Day 2026 countdown.

Find the exact date of Memorial Day in 2024. See the weekday and Memorial Day weekend range for planning.

Find the exact date of Memorial Day in 2027, including weekday details and the long-weekend range.

Find the exact date of Memorial Day in 2028, with weekday and Memorial Day weekend information.

Find the exact date of Memorial Day in 2029, including weekday and long-weekend range.

Find the exact date of Memorial Day in 2030. Includes weekday and Memorial Day weekend range.

Track how many days, weeks, and weekends are left until the next Memorial Day weekend. See when the long weekend starts and plan ahead.

Count down the days and weeks until Memorial Day weekend 2025. See when the long weekend begins and how many days you have left to plan.

Live countdown to the next Martin Luther King Jr. Day. See how many days, weeks, hours, minutes, and seconds remain until the upcoming MLK Day.

Live countdown to Martin Luther King Jr. Day 2024. See how many days, weeks, hours, minutes, and seconds remain until MLK Day 2024.

Live countdown to Martin Luther King Jr. Day 2025. See how many days, weeks, hours, minutes, and seconds remain until MLK Day 2025.

Live countdown to Martin Luther King Jr. Day 2026. See how many days, weeks, hours, minutes, and seconds remain until MLK Day 2026.

Live countdown to Martin Luther King Jr. Day 2027. See how many days, weeks, hours, minutes, and seconds remain until MLK Day 2027.

Live countdown to Martin Luther King Jr. Day 2028. See how many days, weeks, hours, minutes, and seconds remain until MLK Day 2028.

Live countdown to Martin Luther King Jr. Day 2029. See how many days, weeks, hours, minutes, and seconds remain until MLK Day 2029.

Calculate how old Martin Luther King Jr. would be today and on any date. See his actual birthdate, age at death, and use our interactive age calculator.

Find out how old Martin Luther King Jr. would be in 2024 based on his real birthdate, January 15, 1929. Includes age breakdown in years, months, and days.

Find out how old Martin Luther King Jr. would be in 2025 based on his real birthdate, January 15, 1929. Includes age breakdown in years, months, and days.

Find out how many days, weeks, Mondays, or business days are left until Memorial Day 2025. This countdown updates daily and includes Memorial Day weekend details.

Find the exact date 12 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 10 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 6 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 7 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 19 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 30 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 40 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 45 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 60 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 90 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 100 days before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 12 weeks before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 9 months before Christmas. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date and number of days before Christmas 2025. Includes weekday, ISO date, weeks/months and planning use cases.

Find the exact date 50 days after Christmas. Useful for planning deadlines, cycles, and schedules.

Find the exact date 9 months after Christmas. Useful for planning deadlines, cycles, and schedules.

Find the exact date 9 months from Christmas. Useful for planning deadlines, cycles, and schedules.

Calculate how many days, weeks, and months have passed since Christmas. Updates daily.

Live countdown showing days, weeks, weekdays until Christmas. Updated daily.

Calculate how many days, weeks, and months have passed since Christmas Eve. Updates daily.

Find the exact number of days between Thanksgiving and Christmas. Includes per-year calculations.

Find the exact number of days between Halloween and Christmas. Includes per-year calculations.

Find the exact date of Thanksgiving for any year. This calculator instantly tells you which day Thanksgiving falls on, based on the U.S. rule: the fourth Thursday in November.

Instant countdown to Thanksgiving. See how many days are left until the next U.S. Thanksgiving holiday. Auto-calculated daily.

See when Thanksgiving fell in past years. Instantly generate a list of Thanksgiving dates for the last 5, 10, 20, or custom year ranges.

See all years when U.S. Thanksgiving fell on November 28. Instant lookup based on the U.S. fourth-Thursday rule.

Find the exact date 30 days before Thanksgiving for any year. This calculator uses the U.S. fourth-Thursday rule to give fast, accurate results.

Quickly find the exact date 12 days before Thanksgiving for any year. Perfect for planning holiday events, travel, and work schedules.

See what date falls 7 days before Thanksgiving for any year. This one-week-before-Thanksgiving calculator is ideal for travel and shopping plans.

Find the exact date 3 days before Thanksgiving for any year. Useful for booking flights, driving plans, and last-minute holiday prep.

See the exact date 1 day after Thanksgiving for any year. Instantly find when Black Friday falls using the U.S. Thanksgiving date rule.

Find the exact date 30 days after Thanksgiving for any year. Great for end-of-year planning and holiday follow-up scheduling.

Calculate the exact date 50 days after Thanksgiving for any year. Uses the official U.S. fourth-Thursday rule for accuracy.

See what date falls 90 days after Thanksgiving for any year. A three-month-after-Thanksgiving calculator for long-term planning.

Live New Year countdown showing how many days, weeks, hours, minutes, and seconds are left until New Year's Eve and New Year's Day.

See how many days and weeks are left until January 1 (New Year's Day). Live countdown timer with days, weeks, hours, minutes, and seconds.

Find out how many days, weeks, and months have passed since New Year's Day for any year. Useful for tracking goals, timelines, and events.

See how many days and weeks are left until the end of the year (December 31). Live end-of-year countdown for planning and goals.

Find out how many days, weeks, months, hours, and seconds are left until 2025. Live 2025 countdown calculator using your local time.

Find out how many days, weeks, months, hours, and seconds are left until 2026. Live 2026 countdown calculator using your local time.

Find out how many days, weeks, months, hours, and seconds are left until 2027. Live 2027 countdown calculator using your local time.

Find out how many days, weeks, months, hours, and seconds are left until 2028. Live 2028 countdown calculator using your local time.

Find out how many days, weeks, months, hours, and seconds are left until 2029. Live 2029 countdown calculator using your local time.

Find out how many days, weeks, months, hours, and seconds are left until 2030. Live 2030 countdown calculator using your local time.

Find the exact date of Presidents Day for any year from 1900 to 2100. Includes a complete table of Presidents Day dates from 2000 to 2035, long weekend information, and calculation rules.

Find the exact date of Presidents Day in 2026. Includes weekday, long weekend dates, and how this date is calculated.

Find the exact date of Presidents Day in 2027, including weekday, long weekend dates, and date calculation rules.

Live countdown to the next Presidents Day. See days, weeks, hours, minutes, and seconds until the upcoming holiday.

Find the exact date of Juneteenth for any year. Learn when Juneteenth is celebrated, why it matters, and how it is observed nationwide.

Live countdown to the next Juneteenth. See how many days, hours, minutes, and seconds remain until June 19.

Find the exact date and weekday of Juneteenth in 2024.

Find the exact date and weekday of Juneteenth in 2025.

Find the exact date and weekday of Juneteenth in 2026.

Find the exact date and day of the week for Independence Day (4th of July) for any year. See if it creates a long weekend and explore a full 2000–2035 July 4th calendar.

Live countdown to the next Independence Day (4th of July). See how many days, weeks, hours, minutes, and seconds remain until July 4.

Independence Day 2024 falls on Thursday, July 4. Since it's midweek, many people take Friday off for a four-day weekend. This year marks the 248th anniversary of American independence.

Independence Day 2025 falls on Friday, July 4, creating a perfect three-day weekend. Plan your celebrations early for this ideal long weekend holiday marking the 249th anniversary.

Independence Day 2026 falls on Saturday, July 4. Federal observance moves to Friday, July 3, creating a long weekend. This is the historic 250th anniversary of the Declaration of Independence.

Independence Day 2027 falls on Sunday, July 4. Federal observance moves to Monday, July 5, creating a long weekend from Saturday through Monday for extended celebrations.

Independence Day 2028 falls on Tuesday, July 4. Many people take Monday off to create a four-day weekend. This year marks the 252nd anniversary of American independence.

Independence Day 2029 falls on Wednesday, July 4. Taking Tuesday and Thursday off creates a five-day weekend. This year marks the 253rd anniversary of the Declaration of Independence.

Independence Day 2030 falls on Thursday, July 4. Taking Friday off creates a four-day weekend. This year marks the 254th anniversary of American independence.

Calculate the perfect sugar syrup ratio for beekeeping and food preservation. Free online tool for making sugar syrup solutions for bees and cooking.

Estimate how far your boat or vehicle can travel based on tank capacity, fuel burn rate, and speed. View range in NM, miles, and kilometers.

Calculate the perfect oil-to-gas ratio for your 2-stroke engine. Supports 50:1, 40:1, 32:1 ratios for chainsaws, outboards, dirt bikes, and more.

Easily calculate how much 2-stroke oil to mix with gas at a 50:1 ratio. Perfect for chainsaws, outboards, trimmers, and other small engines.

Calculate how much 2-stroke oil to mix with gasoline at a 25:1 ratio. Learn why older engines and vintage tools require this richer oil mixture.

Quickly find how much 2-stroke oil to mix with gas at a 32:1 ratio. Ideal for older chainsaws, trimmers, and high-RPM tools.

Find the right 2-stroke fuel mix at 40:1. Learn why this balanced ratio protects engines while reducing smoke.

Estimate your boat trip distance, time, and fuel use. Enter speed and distance to plan your voyage efficiently.

Estimate boat fuel use per hour and per distance. Enter power, fuel type, speed, and trip to get L/h, GPH, total fuel, cost, and range.

Estimate Mercury outboard engine fuel consumption by model, RPM, speed, and conditions. Get L/h, GPH, fuel per mile, total fuel, and trip cost for FourStroke, Pro XS, Verado, SeaPro, and Racing.

Estimate Mercury 600 Verado V12 fuel consumption by RPM, load, speed, and sea state. Get L/h, GPH, fuel per mile, total fuel, and trip cost with cruise guidance.

Estimate Mercury 400 Verado V10 fuel consumption by RPM, load, speed, and sea state. Get L/h, GPH, fuel per mile, total fuel, and trip cost with prop guidance.

Estimate Mercury Racing 500R fuel consumption by RPM, load, speed, and sea state. Get L/h, GPH, fuel per mile, total fuel, and trip cost with safety margins.

Quickly and accurately convert between square meters, hectares, square kilometers, acres, and square feet for various area calculations.

Convert between file size units (bytes, KB, MB, GB, TB, PB) and compare storage sizes. Free online file size converter tool.