Time Add/Subtract Calculator
Add or subtract hours, minutes, and seconds. Useful for timing experiments, podcast lengths, project planning, or workout splits.
Inputs
Total
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In decimal hours
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In minutes
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In seconds
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H:M:S format
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About Time Add/Subtract Calculator
Decimal hours vs HMS
1.5 hours = 1h 30m. Payroll typically uses decimal hours. Time conversion: minutes/60 = decimal portion. So 1h 45m = 1 + 45/60 = 1.75 hours.
Negative results
Subtracting a larger time from a smaller one produces a negative result. The calculator displays this with a leading minus sign in all formats.
Time zone math
For time across zones (e.g., 8 AM PT + 3 hours = 11 AM PT but 2 PM ET), use the Time Zone Converter — this calculator handles raw durations only.