Add Time Calculator
The Add Time Calculator adds two durations entered as hours, minutes, and seconds, and returns the combined time. It carries every 60 seconds into a minute and every 60 minutes into an hour, and also shows the total in decimal hours and total seconds.
Formula
Total = (duration 1 in seconds) + (duration 2 in seconds), converted back to H:MM:SS
- Each duration is converted to seconds, the two are added, and the total is split back into hours, minutes, and seconds.
- Every 60 seconds carries into a minute and every 60 minutes carries into an hour automatically.
- The total is also shown in decimal hours (seconds ÷ 3600) and as a plain second count.
- To add a duration to a clock time, use the Add or Subtract Time calculator instead.
Example Calculation
Inputs
- First duration — hours: 1
- First duration — minutes: 30
- First duration — seconds: 0
- Second duration — hours: 0
- Second duration — minutes: 45
- Second duration — seconds: 30
Add 1h 30m 00s and 0h 45m 30s: 5400 + 2730 = 8130 seconds, which is 2h 15m 30s (2.258 hours).
Frequently asked questions
What does this calculator do?
It adds two durations given in hours, minutes, and seconds and returns the combined time, carrying seconds and minutes correctly.
Does it handle values over 60?
Yes. Seconds of 60 or more roll into minutes, and minutes of 60 or more roll into hours.
What is the decimal hours output for?
It expresses the total as a single decimal number of hours, which is convenient for timesheets and billing.
Can I add more than two durations?
Add the first two, then feed the running total back in as one of the durations for the next addition.
How is this different from adding to a clock time?
This adds durations together. To find what time it will be after a duration, use the Add or Subtract Time calculator.