Calculators & everyday tools
6 toolsCalculators and everyday tools cover percentages, BMI, age, D-day counts, a timer, and a random picker, all calculated in your browser.
- Percentage calculatorWork out a percent of a number, what percent one number is of another, and percent change in your browser.
- BMI calculatorCalculate adult BMI from height in cm and weight in kg in your browser, with the standard range shown.
- Age calculatorFind the international (man) age from a birth date and a reference date in your browser.
- D-day calculatorCount the days to or since a target date, with an option to count the start day as day 1, in your browser.
- TimerSet minutes and seconds, start the countdown, and hear a short sound when it ends, all in your browser.
- Random pickerPaste a list of names and pick winners at random without repeats, in your browser.
About this category (why · how · FAQ)
Why calculate in the browser
The numbers, dates, and name lists you type can be personal. These tools work inside this browser tab, so what you enter is not sent to a server or saved, and the result appears as soon as you type.
How the calculators and everyday tools work
- Pick the tool: percentage calculator, BMI calculator, age calculator, D-day calculator, timer, or random picker.
- Type the numbers, dates, or names the tool asks for.
- Read the result that appears right away, or press the start or draw button for the timer and the random picker.
- Change the input to calculate again. Nothing is stored, so closing the tab clears it.
Frequently asked questions
- Is what I type uploaded or saved?
- No. The calculators and everyday tools work in your browser and do not send your input to a server or store it.
- Can I use the BMI result as medical advice?
- No. BMI is a general adult guide based on height and weight. For health decisions, ask a doctor.
- Does the timer work if I switch to another tab?
- Yes. The timer counts down to a fixed end time, so the remaining time stays correct even when the tab is in the background.