Working shown on the page
Many calculators show the formula next to the answer, so a teacher, client or colleague can follow it.
32 free tools
Free online calculators
Percentages, averages and medians, ages and date differences, grades and GPA, unit and number conversions, BMI, calories and due dates, plus a scientific calculator for complex numbers and equations. Timers, a wheel of names, dice, a coin flip, a world clock and a weather checker are here too.
30 of 32 run in your browser
Every tool in this category
Sorted A to Z. All free, with no account and no sign-up.
Good to know
How these tools work
Works on any device
Everything runs in the browser and stays usable on a phone. Only the weather checker and the world clock's place search call our server.
Health results are estimates
BMI, calorie, sleep and due date results are general estimates, not medical advice.
Questions
Frequently asked questions
Do I need to install anything?+
No. Every calculator runs in a web browser on a computer, tablet or phone, with no account and no download.
Which calculators use the internet?+
Two. The weather checker fetches forecasts through our server, and Time in X looks up the places you search for. Every other calculator works without sending what you type anywhere.
How precise is the scientific calculator?+
It is built on the mathjs library and handles complex numbers, equations and numerical calculus. As with any floating-point calculator, the last digits of very large or very small results can be rounded.
Keep exploring
Other categories
Everything runs in your browser, so a signed contract never leaves your computer. Most of these take files up to 75 MB and 500 pages.
Business
Invoices, receipts and quotes print to an A4 PDF straight from the page. The CV maker and Kanban board save as you go, in this browser rather than an account.
Documents
Draw a signature with a mouse, trackpad or finger, or type one, then download it as a transparent PNG, an SVG or a JPG.
Writing and text
Counters for words, characters, syllables and reading time, a text diff, a notepad that saves locally, and a typing test that compares you with the last hour of results.
Images
Nine of these send the image to our server, where it is converted in memory and not kept. The other eight, including HEIC to JPG and the cropper, never upload anything.
Finance
Loans, mortgages, take-home pay, sales tax, tips, a monthly budget and a splitter for shared costs. The budget and the group ledgers are saved in this browser.
Developer
JSON, regex, hashes, UUIDs, JWTs and subnets, plus tests for your keyboard, click speed, dead pixels and refresh rate.
Music
A metronome with swing and accents, a pitch pipe, tap tempo, the circle of fifths, and a transposer that reads ChordPro chord sheets.
Audio and video
Check a microphone, speakers or webcam before a call, watch sound on a spectrum analyzer, or record from your webcam. Recordings stay in the tab until you save them.
Crypto
Profit and loss, DCA, staking, gas fees and liquidation prices. Nothing connects to a wallet or a price feed; you type the numbers in.
More focused tools, ready when you are.
Explore the growing collection for calculations, documents, writing, and everyday work.