VARYVIA GUIDE
How to add, subtract and convert hours and minutes
Practical examples for adding time, borrowing an hour when subtracting minutes, and converting time to decimal hours.
Adding hours and minutes
Add the minutes first. For example, 1 hour 45 minutes plus 2 hours 35 minutes equals 3 hours and 80 minutes, which is 4 hours and 20 minutes.
Subtracting with borrowing
For 5 hours 10 minutes minus 2 hours 40 minutes, borrow one hour: 4 hours 70 minutes minus 2 hours 40 minutes equals 2 hours 30 minutes.
Minutes to hours
Divide total minutes by 60. Thus 150 minutes is 2 hours 30 minutes, or 2.5 hours in decimal form.
Decimal hours to minutes
Multiply the fractional part by 60. For example, 1.75 hours is 1 hour plus 0.75 × 60 = 45 minutes.
Avoid a common mistake
1 hour 30 minutes is not 1.30 decimal hours. Use 1.5 when the field expects decimal hours.