General tools
Everyday calculators, converters, timers, and randomizers - simple, single-purpose, and instant.
Open My Screen Your personal dashboard - add tools from any category onto one page.
Health
-
BMI calculator
Calculate your Body Mass Index in your browser, in metric or imperial units, and see which WHO weight category it falls in. Nothing leaves your machine.
-
Sleep cycle calculator
Work out the best times to sleep or wake in your browser - count back from a wake-up time or forward from bedtime in 90-minute sleep cycles. Nothing leaves your machine.
-
TDEE and calorie calculator
Estimate your daily calorie needs in your browser - BMR and total daily energy expenditure from your stats and activity level, with calorie targets to lose, maintain, or gain. Nothing leaves your machine.
Finance
-
Tip calculator
Calculate a tip and split the bill in your browser - set the tip percentage and party size, round up if you like, and see the per-person total. Nothing leaves your machine.
-
VAT and sales tax calculator
Add or remove VAT and sales tax in your browser - enter a price and a rate to find the net, the tax, and the gross total, either direction. Nothing leaves your machine.
-
Compound interest calculator
See how savings grow in your browser - compound interest on a starting balance plus monthly contributions, with the final balance, total interest, and a year-by-year chart. Nothing leaves your machine.
-
Loan and mortgage calculator
Work out loan and mortgage repayments in your browser - monthly payment, total interest, and a year-by-year amortization chart from the amount, rate, and term. Nothing leaves your machine.
Date & time
-
Age calculator
Work out an exact age in your browser - years, months, and days from a birthdate, days until the next birthday, and total days, weeks, and hours lived. Nothing leaves your machine.
-
Due date calculator
Estimate a pregnancy due date in your browser from your last period, conception date, or IVF transfer, and see how far along you are today. Nothing leaves your machine.
-
Countdown to a date
A live countdown to any date in your browser - pick the day, name the event, and watch the days, hours, minutes, and seconds tick down. Copy a shareable link. Nothing leaves your machine.
-
Date difference calculator
Count the days between two dates in your browser - total days, weeks, a years-months-days breakdown, and working days - or add and subtract days and business days. Nothing leaves your machine.
Converter
-
Roman numeral converter
Convert between Roman numerals and numbers in your browser - type either side and it translates live, from 1 to 3999, with validation. Nothing leaves your machine.
-
Unit converter
Convert between units of length, weight, temperature, volume, area, speed, and digital storage in your browser - km to miles, C to F, kg to lb, and more. Nothing leaves your machine.
-
Shoe and clothing size converter
Convert shoe and clothing sizes between US, UK, EU, and centimetres in your browser - pick a size and read the equivalents across regions. Nothing leaves your machine.
Randomizer
-
Team randomizer
Shuffle a list of names into random teams in your browser - split by number of teams or by team size, with a cryptographically fair shuffle. Nothing leaves your machine.
-
Wheel of names
Spin a wheel of names in your browser - type your list, give it a spin, and let a cryptographically fair draw pick a random winner. Nothing leaves your machine.
-
Decision maker
Let chance decide in your browser - flip a coin, get a yes or no, or pick one of your own options at random. Nothing leaves your machine.
-
Random number generator
Generate random numbers in your browser - set a min and max, pick how many you want, and toggle unique (no repeats), backed by a cryptographically fair generator. Nothing leaves your machine.
-
Secret Santa generator
Draw Secret Santa assignments in your browser - paste your names, add exclusion pairs so couples never match, and reveal each gift-giver privately. A cryptographically fair draw. Nothing leaves your machine.
Timer
-
Timer and stopwatch
A countdown timer and stopwatch in your browser - set a time and count down (it keeps counting once time is up), or count up with laps. Nothing leaves your machine.
-
Pomodoro timer
A pomodoro focus timer in your browser - work and break cycles with adjustable, saved durations and a longer break every few rounds. Nothing leaves your machine.