How do I add or subtract hours and minutes?
Type the durations on one line with + or -, for example 5h 30m + 2h 15m or 40h - 6h 30m, then read the total. Use full words or shorthand (h, m, d, w).
Support
Need a hand with Time Calculator? Email us and we read every message. The answers below cover the questions we get most.
Emailsupport@cardamon.org
Tell us what you tried and what you expected, and add a screenshot if you can.
Common questions
Can I multiply or divide a duration?
Yes. Type * to multiply and / to divide, for example 90m * 3 or 3d 4h / 2. On a keyboard the operators are + - * /. The mobile app also has × and ÷ keys on its keypad.
How do I convert hours to minutes or decimal hours?
Open Convert to see the result in every unit from years down to milliseconds, or pick a format from "Show result as", including decimal hours and clock styles like H:MM:SS.
How do I calculate a time difference?
Subtract one duration from another, for example 40h - 6h 30m, and the calculator shows the remaining time.
Is my data private?
Yes. The calculator runs on your device. It makes no network calls and collects no personal data. Your calculation history stays in your browser or on your phone.
Is Time Calculator free?
Yes. The web calculator and the Chrome extension are free. The mobile app is free on Google Play, with an iOS version on the way.
Where can I get the app or the browser extension?
Get it on Google Play, use it on the web at timecalculator.app, or add the Chrome extension to calculate time in your browser side panel.
How do I report a bug or request a feature?
Email support@cardamon.org with what you tried and what you expected. Screenshots help. We read every message.