Time Calculator
Add or subtract any combination of hours, minutes, and seconds.
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How It Works
Adds hours, minutes, and seconds together to get total elapsed time. Handles overflow automatically — 90 minutes becomes 1 hour 30 minutes. Useful for tracking work hours, project time, or cooking.
Formula
Time arithmeticQuick Reference
Common calculations — results you can verify instantly.
2h30 + 1h45
150+105 min
4h 15min
8:30 to 5:00
8.5hrs total
510 minutes
1hr 20min + 45min
80+45
2h 5min
Tips & Shortcuts
For work hours: track start and end times, then subtract.
Overtime: total hours minus 8 standard hours per day.
Time zones: convert everything to UTC before adding to avoid errors.
Common Mistakes
Adding decimal hours to minutes directly
1.5 hours is NOT 1 hour 50 minutes. It is 1 hour 30 minutes. Convert properly.
Forgetting to handle midnight crossover
If a shift starts at 10pm and ends at 6am, the time spans midnight — calculate across two days.
Frequently Asked Questions
2h45m + 3h30m = 5h75m = 6h15m. Convert 75 minutes to 1 hour 15 minutes.
Subtract start from end time. Account for lunch break. Convert total minutes to decimal hours: 7h45m = 7.75 hours.
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