Time Calculator
Add or subtract hours, minutes and seconds — or find the exact duration between two times.
Free Time Calculator — Time Math Made Easy
Adding 2 hours 45 minutes to 11:30 PM shouldn't require mental gymnastics. This time calculator does time arithmetic for you: add or subtract any duration from a start time, or measure the exact gap between two times — with automatic midnight rollover, 12-hour and 24-hour results, and second-level precision.
➕ Add / Subtract
Shift any time forward or backward by hours, minutes and seconds.
🌙 Midnight Rollover
Crossing midnight? A clear +1 day / −1 day badge keeps you oriented.
⏱️ Time Difference
Get the exact duration between two times — overnight spans included.
⚡ Instant & Private
Results update as you type. Nothing ever leaves your browser.
Frequently Asked Questions
Choose the "Add / Subtract" tab, enter your start time, pick + or −, then enter the duration in hours, minutes and seconds. The result appears instantly.
The calculator wraps around the 24-hour clock automatically and shows a "+1 day" (or "−1 day") badge so you always know the result landed on the next or previous day.
Switch to the "Difference" tab and enter both times. If the end time is earlier than the start time, it is treated as the next day — perfect for overnight shifts.
Yes. Both modes accept hours, minutes and seconds, so you can time anything from a sprint to a work shift precisely.
Yes — completely free, with no account required and no data sent to any server.