Hours Calculator
Add or subtract hours and minutes, convert between time units, or find the difference between two times. Switch modes to choose your calculation.
How Hours Calculator works
Adding and subtracting time
The calculator converts all time values to minutes, performs the arithmetic, then converts back to hours and minutes. Negative values for the second time input indicate subtraction. For example, 3 hours 45 minutes plus 2 hours 30 minutes: (3 × 60 + 45) + (2 × 60 + 30) = 225 + 150 = 375 minutes = 6 hours 15 minutes.
Converting between time units
Time conversion uses these relationships: 1 hour = 60 minutes = 3,600 seconds. To convert minutes to hours, divide by 60. To convert hours to seconds, multiply by 3,600. The calculator shows decimal results for precision — for example, 90 minutes = 1.5 hours.
Calculating time differences
Enter two clock times in 24-hour (HH:MM) format. The calculator finds the difference in hours and minutes. If the end time is earlier than the start time, the calculation wraps around midnight — for example, 22:00 to 06:00 gives 8 hours.
Decimal hours explained
Decimal hours express time as a fraction of an hour rather than hours and minutes. This format is widely used for timesheets and billing. For example, 7 hours 45 minutes = 7.75 decimal hours (45 ÷ 60 = 0.75). Common conversions: 15 min = 0.25, 30 min = 0.5, 45 min = 0.75.
Frequently asked questions
How do I convert minutes to hours?
Divide the number of minutes by 60. For example, 150 minutes ÷ 60 = 2.5 hours, which is 2 hours and 30 minutes. To get the remaining minutes, multiply the decimal part by 60: 0.5 × 60 = 30 minutes.
How do I calculate hours worked?
Enter your start time and end time in the "Time difference" mode. The calculator will show the total hours and minutes between the two times. For example, 08:30 to 17:00 = 8 hours 30 minutes. If you took a lunch break, subtract that time using the "Add / subtract" mode.
What are decimal hours?
Decimal hours express time as a single number rather than hours and minutes. 7 hours 30 minutes = 7.5 decimal hours. This format is commonly used for payroll, billing, and project management. Multiply the minutes by 60 to convert the decimal back to minutes.
How do I add hours and minutes together?
Add the hours and minutes separately. If the minutes exceed 60, carry over to hours. For example, 2h 45m + 3h 30m: hours = 2 + 3 = 5, minutes = 45 + 30 = 75. Since 75 > 60, carry 1 hour: 6h 15m. This calculator handles the carry automatically.
How do I calculate overtime hours?
Use the "Time difference" mode to find your total hours worked, then use "Add / subtract" mode to subtract your standard working hours (e.g. 8 hours). The result is your overtime. For example, if you worked from 07:00 to 18:30 (11h 30m) and your standard day is 8 hours, overtime = 3h 30m.
How many minutes are in a day?
There are 1,440 minutes in a day (24 hours × 60 minutes). There are 86,400 seconds in a day (1,440 × 60). A working day of 8 hours contains 480 minutes.
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