Free Online Calculators
Simple, accurate tools for finance, health, math, and everyday life. No sign-ups, no clutter, just calculators that work.
Built for students, homeowners, investors, travelers, and anyone who needs a quick answer.
All Calculators
59 free tools across 4 categories.
💰 Financial Calculators
View allCompound Interest Calculator
See how your money grows with compound interest over time.
Currency Converter
Convert between world currencies with up-to-date rates, swap and search across 150+ currencies.
Discount Calculator
Calculate sale prices and how much you save with any discount.
Extra Payment Calculator
See how extra monthly payments shorten your loan and save interest.
Inflation Calculator
See how inflation erodes purchasing power over time.
Loan Calculator
Estimate monthly payments and total interest for any loan.
Mortgage Calculator
Calculate monthly mortgage payments including taxes and insurance.
Retirement Calculator
Project your retirement savings growth and estimate monthly income in retirement.
Sales Tax Calculator
Add or remove sales tax from any purchase amount.
Tip Calculator
Add a tip, split the bill, and calculate exactly what everyone owes. Pre-tax tipping, service quality, and gratuity checks built in.
💪 Health & Fitness
View allBMI Calculator
Calculate your Body Mass Index and understand what it means.
BMR Calculator
Find your Basal Metabolic Rate. Calories burned at rest.
Body Fat Calculator
Estimate body fat percentage using simple measurements.
Calorie Calculator
Estimate daily calorie needs for weight maintenance, loss, or gain.
Due Date Calculator
Estimate pregnancy due date based on last menstrual period.
Ovulation Calculator
Estimate your ovulation date and fertile window based on your cycle.
Sleep Calculator
Find the best bedtime or wake time based on sleep cycles.
🔢 Math & Conversions
View allBinary Calculator
Convert between binary, octal, and decimal number systems.
Combinations and Permutations
Calculate combinations (nCr) and permutations (nPr) for any values.
Electricity Calculator
Calculate electricity costs for any appliance based on power, usage, and rate.
Factorial Calculator
Calculate the factorial of any number up to 170.
Fraction Calculator
Add, subtract, multiply, and divide fractions, or convert a decimal to its fraction form.
Fuel Cost Calculator
Calculate trip fuel costs based on distance, efficiency, and fuel price.
Hex Calculator
Convert between hexadecimal, decimal, and binary number systems.
Percentage Calculator
Calculate percentages, percentage changes, and more.
Prime Numbers Calculator
Check if a number is prime, find prime factors, and list primes up to any value.
Roman Numeral Converter
Convert between Roman numerals and numbers (1-3999).
Scientific Calculator
Perform advanced math with trigonometric, logarithmic, and exponential functions.
Scientific Notation Converter
Convert between decimal and scientific notation instantly.
Significant Figures Calculator
Count significant figures and round numbers to a specified number of sig figs.
Speed Converter
Convert between mph, km/h, knots, meters per second, and Mach speed.
Ratio Calculator
Simplify ratios and find missing values in proportions.
Time Converter
Convert between seconds, minutes, hours, days, weeks, and more.
Square Root Calculator
Calculate square roots and nth roots of any number.
Unit Converter
Convert between units of length, weight, volume, temperature, and more.
Average Calculator
Find the mean, median, mode, and range of any list of numbers.
Half Life Calculator
Work out how much of a decaying sample is left, or how long it takes to reach a target amount.
Logarithm Calculator
Calculate logarithms in any base, plus antilogs and powers.
Percent Error Calculator
Calculate percent error between an experimental and an accepted value.
Quadratic Equation Solver
Solve any quadratic equation and see the roots, discriminant, and vertex.
Distance Calculator
Find the distance between two points, convert distance units, or get a hypotenuse.
GCD and LCM Calculator
Find the greatest common divisor and least common multiple of any numbers.
Slope Calculator
Find the slope, equation, angle and intercepts of a line from two points.
🛠️ Other Tools
View allAge Calculator
Calculate your exact age in years, months, and days.
Character and Word Counter
Count characters words sentences and more.
Color Converter
Convert colors between HEX RGB and HSL.
Countdown Timer
Set a quick countdown in minutes for focus sessions, breaks, and deadlines.
Date Difference Calculator
Find the exact number of days between two dates.
ETA Calculator
Calculate travel time and estimated arrival.
GPA Calculator
Calculate your grade point average across multiple courses.
Password Strength Checker
Check how strong your password is against common attacks.
Random Number Generator
Generate random numbers within any range.
Stopwatch
A simple accurate stopwatch for timing anything.
Time Zone Converter
Convert times between different time zones.
Timer
Set a precise countdown timer with hours, minutes, and seconds.
Tip Split Calculator
Split a bill evenly between friends and include the tip.
World Clock
View current time in major cities worldwide.
Time Duration Calculator
Find the time between two clock times, handling midnight, or add and subtract time.
Day of the Week Calculator
Find the day of the week for any date, plus week number and day of year.