Calculators
Quick everyday calculators - percentages, BMI and age with exact breakdowns. Type and get the answer instantly.
Percentage Calculator
X% of Y, X is what % of Y, and percentage increase/decrease - three modes.
BMI Calculator
Body Mass Index with metric/imperial toggle, category and healthy range indicator.
Age Calculator
Age in years/months/days from date of birth, totals, weekday born, next birthday countdown.
Unit Converter
Convert length, weight, temperature, area, volume and speed between metric and imperial units.
Stopwatch
Free online stopwatch with millisecond precision, lap times, plus a countdown timer mode.
Pomodoro Timer
A Pomodoro focus timer with customizable session lengths, cycle tracking, a built-in task list and an end-of-session beep.
Random Number Generator
Generate random numbers in any range with crypto-grade randomness. Set the count, allow or block duplicates, and sort the results.
Scientific Calculator
A scientific calculator with trig, logarithms, powers, square root and constants, a real expression parser, calculation history and full keyboard support.
Timezone Converter
Convert a date and time between any time zones, build a custom list of target zones, and check a live world clock of major cities.
Calculators FAQs
- Yes - all calculators are completely free with no sign-up and no usage limits.
- Percentage Calculator, BMI Calculator and Age Calculator.
- Yes. Every calculation happens locally in your browser - nothing is sent to a server or stored.
- The math is exact for the inputs given (including leap-year-correct age math). BMI categories follow WHO cutoffs; they're screening bands, not medical diagnoses.