Time Calculator — Add or Subtract Hours, Minutes, Seconds
Add or subtract two time values in HH:MM:SS form. Returns the result as HH:MM:SS, total decimal hours, and total seconds. Handles values longer than 24 hours.
Result
Result (add)
04:15:30
4.2583 hours · 255.50 minutes · 15,330 seconds
- Time A9,000 seconds total02:30:00
- Time B6,330 seconds total01:45:30
- OperationA + B
- Result (HH:MM:SS)04:15:30
- Result in decimal hours4.2583 hr
- Result in minutes255.50 min
- Result in seconds15,330 s
Step-by-step
- Convert each input to seconds: A = 2×3600 + 30×60 + 0 = 9,000s; B = 6,330s.
- Apply add: 9,000 + 6,330 = 15,330s.
- Convert back to H:M:S: 15,330s ÷ 3600 = 4h remainder 930s. 930s ÷ 60 = 15m remainder 30s.
How to use this calculator
- Enter Time A and Time B as hours, minutes, seconds (each input is bounded — minutes/seconds capped at 59, hours capped at 999).
- Pick + Add or − Subtract.
- Read the result in three formats. The decimal hours form is what most billing systems want (1:30:00 = 1.5 hr).
- Subtraction can return negative results when Time B > Time A — useful for "how much over budget am I" calculations.
About this calculator
Pure time arithmetic — adding or subtracting two time values without converting to/from calendar dates. Useful for billable-hours math, lap-time summation, video editing, audio cue work, and any task where you need to add up clock-style durations. The result is shown in three equivalent forms: HH:MM:SS (clock form), decimal hours (billing form), and total seconds (data-entry form).
Frequently asked
Days Between Dates works on calendar dates (March 15 to April 20). Time Calculator works on pure durations (02:30:00 + 01:45:30). Use this one for "how long is the combined runtime of these 3 videos" or "if I bill 1h45m on task A and 2h10m on task B, what's my total".
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