Free calculators and converters
Free calculators for everyday questions: percentages and discounts, unit conversions and dates. Every answer shows how it was worked out.
- Free
Percentage calculator
13 percentage calculators: change, discount, tax, tip, margin and more. - Free
Unit converter
Convert length, weight, temperature, fuel economy and 9 more. - Free
Date calculator
Days between dates, working days, age, countdowns and week numbers.
Answers you can check
Each calculator shows the formula with your own numbers, so you can follow the working, reuse it in a spreadsheet and trust the result.
Made for every country
Type numbers with a comma or a point as the decimal separator. The unit converter covers metric, US and imperial units side by side, and the date calculator works on the real calendar, including leap years.