Calculators & units
Calculate percentages, fractions and statistics, or convert measurement units.
22 tools in this category. Every tool runs in the browser and needs no sign-up.
Spin the wheel
Spin the wheel to pick a random winner from 2–100 entries. Type one entry per line, spin, remove winners, shuffle or sort, and keep a result history.
Name picker
Random name picker and team generator: paste a list, draw one or more winners without repeats, or split names into balanced random teams, then copy the results.
Dice roller
Online dice roller: roll 1–10 dice with d4, d6, d8, d10, d12, d20 or d100, or type notation like 2d6+3. See each die, the total and your roll history.
Flip a coin
Flip a coin online for heads or tails with a quick 3D flip. Track counts and streaks, or flip up to 1,000 times to see percentages and the longest streak.
BMI calculator
Free BMI calculator for adults in metric or imperial units. See your BMI, its WHO category on a color scale and the healthy weight range for your height.
Random Integer Generator
Generate up to 10,000 integers using Web Crypto. Both bounds are included; repeats are allowed; range is signed 32-bit.
Scientific Notation Converter
Convert decimals and scientific notation using exact decimal text. Up to 10,000 input characters; exponent −10,000 to 10,000.
Bitwise Calculator
Compute AND, OR, XOR, NOT and shifts with arbitrary-size integers. Shift counts are 0–4096; negatives use signed semantics.
Roman Numeral Converter
Convert integers from 1 to 3999 into Roman numerals, or decode canonical Roman notation back to decimal.
Percentage Calculator
Calculate a percentage of a number, one number as a percentage of another, or the percentage change from A to B.
Ratio Simplifier
Reduce integer ratios and image aspect ratios to their simplest form using the greatest common divisor.
Fraction Calculator
Add, subtract, multiply or divide two fractions and get an exactly reduced fraction without floating-point rounding.
Data Size Converter
Convert bytes, decimal kB/MB/GB/TB and binary KiB/MiB/GiB/TiB. See the difference between 1000 and 1024-based units.
Length Converter
Convert meters, kilometers, centimeters, millimeters, inches, feet, yards and miles with one local calculation.
Temperature Converter
Convert Celsius, Fahrenheit and Kelvin. Check common temperatures such as boiling water and absolute zero.
Number List Statistics
Calculate count, sum, minimum, maximum, mean and median for a list of numbers.
Mass Unit Converter
Convert kilograms, grams, milligrams, tonnes, pounds and ounces.
Area Unit Converter
Convert square metric units, hectares, acres, square feet and square inches.
Volume Unit Converter
Convert liters, milliliters, cubic units, US gallons, US fluid ounces and imperial gallons.
Speed Unit Converter
Convert m/s, km/h, mph, ft/s and knots.
Angle Unit Converter
Convert degrees, radians, gradians and full turns.
Duration Unit Converter
Convert milliseconds, seconds, minutes, hours, days and weeks.