Time calculator (add and subtract)
Add or subtract two periods in hours and minutes and get the total in h:min, decimal hours and minutes.
Each period is converted to minutes, the operation is applied, and the total is turned back into hours:minutes.
How the calculation works
To add or subtract time, convert everything to minutes (hours × 60 + minutes), do the math, then convert back: hours are the whole part of dividing by 60, minutes are the remainder. So 2h45 + 1h30 = 255 min = 4h15.
Examples
- 2h45 + 1h30 = 255 min = 4h15.
- 8h00 − 1h20 (break) = 6h40.
Frequently asked questions
Does it work for worked hours?
For adding periods, yes. To calculate from clock-in and clock-out, use the hours worked calculator.
Why isn't 1h30 + 1h45 = 2h75?
Because an hour has 60 minutes, not 100. 30 + 45 = 75 min = 1h15, so the total is 3h15.
How to convert hours to decimal?
Divide minutes by 60: 4h15 = 4 + 15/60 = 4.25 hours.
Related calculators
More Date & Time calculators
See all →Age
Find your exact age in years, months and days from your date of birth.
Days between dates
Count how many days, weeks and months are between two dates.
Add/subtract dates
Add or subtract days, months and years from a date to find the resulting date.
Business days
Count the business days (excluding weekends) between two dates.
Countdown
See how many days, weeks and months are left until any date — a birthday, a trip, an exam or New Year. The result updates on its own.
Age difference
Calculate the age difference between two people from their birth dates.
Day of the week
Find out which day of the week any date fell (or will fall) on.
Leap year
Find out if a year is a leap year, how many days it has and the next leap year.
Updated on June 30, 2026 · by Rafael Rossi · Methodology & sources