Hour Calculator

Add and subtract time or find a duration

Add and subtract time values, or find the duration between two times.

For duration, type a start time and an end time; the result shows the total in hours and minutes. For add/subtract, type a base time and the amount to add or subtract; the new time appears.

Examples

• How long will the offsite last? Make sure Duration is set at the top. Set the start and end times and calculate. Subtract any breaks manually if you need to.
• What's the time X hours after / before now? Use for a simple classroom quiz to teach the time. Set Add / Subtract at the top, a start time, and a number of hours and minutes, then ask students to say the answer before you click Calculate to check.

Related tools

• The Date Calculator calculates the number of days between two dates and adds and subtracts whole days to and from a date.

FAQs

What if the period crosses midnight?

An end time earlier than the start time is treated as the next day, so 22:00 to 06:00 returns 8 hours.

Does it count seconds?

No, hours and minutes only. For precision below a minute use the online stopwatch.

How do I add a number of minutes that crosses an hour boundary?

Type the minutes as a single value (75 minutes, 200 minutes) and the calculator will convert to hours automatically.