Subtract Time Calculator
Subtract one duration from another and get the difference in hours, minutes and seconds — including negative results when the second time is larger.
How to subtract time
To subtract time, take each unit of Time B away from Time A, borrowing from the next unit up when needed. If the result goes below zero it is shown with a minus sign as a normalised duration.
Use it to find time remaining, how much a task ran over, or the gap between two durations. Enter the larger value as Time A for a positive answer, or either way to see the signed difference.
Frequently asked questions
Can the result be negative?
Yes. If Time B is larger than Time A, the answer is shown with a minus sign, expressed as a normalised duration in hours, minutes and seconds.
How does borrowing work when subtracting time?
When a unit would go negative, the calculator borrows from the next unit up — one hour becomes 60 minutes, one minute becomes 60 seconds — so the result is always tidy.
Is this the same as time between two clock times?
Not quite. This subtracts two durations you type in. To find elapsed time between two clock times like 9:15 AM and 5:45 PM, use the duration tool on the all-in-one calculator.