Calculators
Math, health, everyday math
20 tools in this category
Body Fat Calculator
Estimate your body fat percentage instantly using the U.S. Navy method — just enter a few body measurements, no scale needed.
Water Intake Calculator
Calculate your ideal daily water intake based on weight, activity level, and climate — free and instant.
Age Calculator
Calculate your exact age in years, months, and days instantly. Free and easy to use.
BMI Calculator
Calculate your Body Mass Index (BMI) and check your health category instantly.
Percentage Calculator
Calculate percentages, percentage change, and ratios instantly. Free, fast, and easy to use.
Stopwatch & Timer
Free online stopwatch with lap times plus a countdown timer with an alert sound. No signup needed.
Date Calculator
Calculate the exact duration between two dates or add and subtract days from any date. Free and instant.
Calorie Calculator
Calculate your daily calorie needs (TDEE) based on BMR, age, weight, height, and activity level.
Roman Numeral Converter
Convert numbers to Roman numerals and back instantly. Free, accurate, and easy to use.
Sleep Calculator
Find the best bedtime or wake-up time based on 90-minute sleep cycles so you wake up refreshed.
Standard Deviation Calculator
Calculate mean, variance, and standard deviation for sample or population data sets instantly.
Random Number Generator
Generate random numbers with custom range, count, uniqueness, and decimals. Free and instant.
Scientific Calculator
Full-featured scientific calculator with trig, logarithms, powers, roots, and constants.
Average Calculator
Find the mean, median, mode, and range of any data set instantly. Free and private.
Fraction Calculator
Add, subtract, multiply, and divide fractions with simplified results, decimals, and percentages.
Percentage Change Calculator
Calculate percentage increase or decrease between two values, or apply a percent change to any number.
Pregnancy Due Date Calculator
Estimate your due date from your last period, conception date, or due date, with current week and trimester.
Dog Age Calculator
Convert your dog\u2019s age to human years with a science-based formula adjusted for breed size.
Ratio Calculator
Simplify ratios, find missing ratio terms and split quantities in a ratio. Free online ratio calculator.
Long Division Calculator
Solve long division with remainders and step-by-step work shown. Free long division solver for homework.