Time calculator
Add or subtract two lengths of time and read the result every way you need it.
Hours · Minutes · Seconds
Hours · Minutes · Seconds
Result
Adding and subtracting time
Time math is awkward because hours, minutes, and seconds do not use base ten. This calculator converts each duration to seconds, adds or subtracts them, then converts the answer back into clean hours, minutes, and seconds. It also shows the result as a decimal number of hours, which is handy for timesheets and billing.
Worked example
Adding 2 hours 30 minutes and 1 hour 45 minutes 30 seconds gives 4 hours 15 minutes 30 seconds, or 4.26 hours, or 15,330 seconds. Switch to subtract to find the gap between two durations.
Frequently asked questions
How do I add up hours and minutes?
Enter each duration in the hours, minutes, and seconds fields, keep the operation on add, and the calculator returns the combined time in several formats at once.
How do I subtract one time from another?
Set the operation to subtract. The calculator takes the second duration away from the first and shows the result, including a negative value if the second is longer.
How do I convert minutes to hours?
Divide the minutes by 60. The calculator does this automatically and reports your total as decimal hours, so 90 minutes shows as 1.50 hours.
What is the difference between a duration and a time of day?
A duration is a length of time, like 2 hours 30 minutes. This tool adds and subtracts durations. To find hours worked between two clock times, use the Work Hours Calculator.
Why use seconds at all?
Converting everything to seconds avoids carrying and borrowing across the 60-minute and 60-second boundaries, which keeps the arithmetic exact.