How do I add hours and minutes?

Enter both durations and the calculator returns the total. Switch the operator to subtract for the difference.

How do I calculate hours between two times?

Use Difference mode. Enter the start and end clock time. If the end is earlier, the calculator assumes it is the next day.

Can I use 12-hour or 24-hour formats?

Both. Type 09:00 or 9:00 AM in either field. The calculator parses both.

Time Calculator

Two modes: add or subtract durations (hours, minutes, seconds), or calculate the elapsed time between a start and end clock time.

By Numerly · Updated June 14, 2026

Time A

Hours

Minutes

Seconds

Add

Time B

Hours

Minutes

Seconds

Result

2h 15m 00s

Total seconds

8,100 s

How it works

Add mode: convert each duration to seconds, add or subtract, then format back. Difference mode: convert both clock times to seconds since midnight, subtract end − start, and handle the next-day rollover for overnight ranges.

Frequently asked

How do I add hours and minutes?: Enter both durations and the calculator returns the total. Switch the operator to subtract for the difference.
How do I calculate hours between two times?: Use Difference mode. Enter the start and end clock time. If the end is earlier, the calculator assumes it is the next day.
Can I use 12-hour or 24-hour formats?: Both. Type 09:00 or 9:00 AM in either field. The calculator parses both.

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