Pro Calculators and Guides
How to Add and Subtract Time: Days, Hours, Minutes and Seconds
Add or subtract durations such as 2 h 45 min and 1 h 30 min, and see totals in hours, minutes and seconds. Useful for work hours, travel and cooking.
Saizul Amin15 Oct 2026 · Updated 17 Oct 2026 · 1 min read
Time does not use base ten, so ordinary calculators fail: 1 h 45 min plus 2 h 30 min is not 3.75. It is 4 h 15 min. A time calculator handles the carrying for you.
Quick answer
Enter durations in days, hours, minutes and seconds, choose add or subtract, and read the result in days, hours, minutes and seconds, and also as total hours, minutes and seconds.
Doing it by hand
- Add minutes: 45 + 30 = 75 minutes = 1 hour and 15 minutes.
- Add hours: 1 + 2 = 3, plus the carried 1 = 4.
- Result: 4 h 15 min.
To subtract, borrow 60 minutes from the hours when needed.
Where it helps
- Work hours across several shifts.
- Travel time for a journey with legs and waits.
- Cooking schedules with several steps.
- Editing video or audio lengths.
- Training plans with sets and rests.
Steps
- Enter the first duration.
- Choose add or subtract.
- Enter the second duration.
- Read the total.
Decimal hours
For pay, convert minutes to decimals: 15 min = 0.25 h, 30 min = 0.5 h, 45 min = 0.75 h. So 4 h 15 min = 4.25 h.
Tips
- For clock times (start and end) use the Work Hours Calculator.
- For dates, use the Date Difference Calculator.
