Time Calculator — Add, Subtract & Convert Time

To add hours and minutes, add the hours together and the minutes together separately. If the minutes total 60 or more, convert 60 minutes into 1 hour and add it to the hours. For example, 2 hours 45 minutes + 1 hour 30 minutes = 3 hours 75 minutes = 4 hours 15 minutes. Our calculator handles this conversion automatically.

To convert decimal hours to hours and minutes, the whole number part is the hours, and multiply the decimal part by 60 to get the minutes. For example, 7.5 hours = 7 hours + (0.5 x 60) minutes = 7 hours 30 minutes. Similarly, 3.75 hours = 3 hours 45 minutes, and 8.25 hours = 8 hours 15 minutes.

To calculate the duration between two times, subtract the start time from the end time. If the end time is earlier than the start time (e.g., crossing midnight), add 24 hours to the end time before subtracting. For example, from 9:30 AM to 5:15 PM = 7 hours 45 minutes. From 10:00 PM to 2:30 AM = 4 hours 30 minutes.

7.5 hours equals 7 hours and 30 minutes. The 0.5 decimal part represents half an hour: 0.5 x 60 = 30 minutes. This is a very common conversion needed for work timesheets, as many employees log 7.5 or 8.5 hour workdays. Other common conversions: 7.25 hours = 7 hours 15 minutes, 7.75 hours = 7 hours 45 minutes.