Time Calculator

Add or subtract hours, minutes and seconds, with decimal hours.

How to add and subtract time

Time uses base 60, so 60 seconds make a minute and 60 minutes make an hour. The calculator converts both times to seconds, adds or subtracts them, and turns the total back into hours, minutes and seconds. Doing it by hand, carry over every 60 seconds or 60 minutes.

Worked examples

• 2 h 45 min 30 sec + 1 h 30 min 45 sec: the seconds add to 75 (1 min 15 sec), the minutes to 76 (1 h 16 min), so the result is 4 h 16 min 15 sec. That is 4.2708 decimal hours.
• 5 h 20 min − 2 h 45 min: 2 h 35 min, which is 2.5833 hours or 155 minutes.
• 1 h − 2 h 30 min: −1 h 30 min. A minus sign means the second time is longer.

Minutes as decimal hours

Payroll often needs decimal hours. Divide the minutes by 60: 15 minutes is 0.25 hours, 30 minutes is 0.5 hours and 45 minutes is 0.75 hours.

Frequently asked questions

Can the result be more than 24 hours?

Yes. This calculator adds durations, so 20 hours plus 10 hours is 30 hours rather than a time of day.

How do I convert hours and minutes to decimal hours?

Add the hours to the minutes divided by 60. For example, 4 hours 16 minutes is 4 + 16 / 60, which is 4.2667 hours.

What does a negative result mean?

It means the time you subtracted is longer than the first time. The minus sign shows how much longer.

Can I add more than two times?

Add two, then use the result as Time 1 and add the next one.