Calculators & utilities
Work out percentages, dates, units and more.
20 tools
Clear calculators, with the assumptions on show
Discounts, VAT, loans, compound interest, pay, dates, age, units, time zones and more. Each result explains how it is calculated and makes clear that it is an estimate.
- Calculations run in your browser, with no data sent
- No accounts or paid services
- VAT rates and financial results are indicative
Also in Developer & data tools: Percentage calculator · Byte & file size converter · Binary, decimal & hexadecimal converter · UUID generator
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Discount calculator
Work out the final price, how much you save and, optionally, the tax applied to the discounted price.
AvailableIn your browser - Available
VAT / IVA calculator
Add VAT to a net amount or extract VAT from a VAT-inclusive amount. Configurable rate with 21% as an example.
AvailableIn your browser - Available
Loan calculator
Estimate the monthly payment, total repaid and interest of a loan with an amortisation schedule. Indicative only.
AvailableIn your browser - Available
Compound interest calculator
Project a balance from an initial amount, regular contributions, rate and duration. No returns are guaranteed.
AvailableIn your browser - Available
Salary & hourly rate calculator
Convert between hourly, daily, weekly, monthly and annual pay using your hours and weeks. Tax is not included.
AvailableIn your browser - Available
Date calculator
Count the days between two dates or add and subtract days from a date, with leap years and business days.
AvailableIn your browser - Available
Age calculator
Work out an exact age in years, months and days and the days until the next birthday. Nothing is saved or sent.
AvailableIn your browser - Available
Unit converter
Convert length, weight, temperature, area, volume and speed with exact factors and explicit units.
AvailableIn your browser - Available
Time zone converter
Convert a date and time between time zones, showing the UTC offset and daylight saving from your browser.
AvailableIn your browser - Available
Scientific calculator
Calculator with parentheses, powers, factorial and trigonometric, logarithm and root functions. No eval.
AvailableIn your browser - Available
Password generator
Generate strong random passwords with the browser's cryptographic generator. Never sent or stored.
AvailableIn your browser - Available
Password strength checker
Estimate a password's strength in your browser and spot weak patterns. It is never sent or stored.
AvailableIn your browser - Available
Random number generator
Generate unbiased random whole numbers in a range, with an option to avoid repeats. Uses Web Crypto.
AvailableIn your browser - Available
Stopwatch & countdown timer
Stopwatch with laps and a countdown timer with an optional sound alert. Stays accurate when the tab is in the background.
AvailableIn your browser - Available
Invoice total calculator
Add line items with quantities, discounts and configurable VAT to get net, VAT per rate and total. Download CSV.
AvailableIn your browser - Available
Colour contrast checker
Calculate the WCAG contrast ratio between text and background colours and check AA and AAA levels.
AvailableIn your browser - Available
Time duration calculator
Calculate the time between two clock times (overnight and with breaks) and add or subtract durations in h:mm:ss and decimal hours.
AvailableIn your browser - Available
Aspect ratio calculator
Simplify a ratio (1920×1080 → 16:9) and find the missing width or height that keeps it.
AvailableIn your browser - Available
Image size and DPI calculator
Convert pixels to centimetres or inches at a resolution (DPI) and back, with megapixels and uncompressed size.
AvailableIn your browser - Available
Basic calculator
Simple calculator with addition, subtraction, multiplication, division, brackets and percent. Works with the keyboard.
AvailableIn your browser