A time-duration conversion chart shows equivalent values in hours, minutes, seconds, and decimal hours. For example, 30 minutes equal 0.5 hours and 1,800 seconds, while 45 minutes equal 0.75 hours and 2,700 seconds.
Calculate elapsed hours and minutes, overnight duration, break deductions, decimal hours, total minutes, and seconds.
Hours, minutes, seconds, and decimal hours describe the same elapsed amount using different scales.
Time Duration Conversion Formulas
Multiply hours by 60 to convert them into minutes.
Multiply minutes by 60 to convert them into seconds.
Divide minutes by 60 to convert them into decimal hours.
Hours to Minutes
Each hour contains 60 minutes.
Two hours equal 120 minutes, while eight hours equal 480 minutes.
Multiply the hour value by 60.
Minutes to Hours
Divide total minutes by 60.
The quotient gives complete hours and the remainder gives additional minutes.
For example, 150 minutes equal two hours 30 minutes.
Minutes to Decimal Hours
Divide the minute value by 60.
Thirty minutes equal 0.5 hours.
Forty-five minutes equal 0.75 hours.
Minutes to Seconds
Each minute contains 60 seconds.
Multiply the minute value by 60.
For example, 30 minutes equal 1,800 seconds.
Hours to Seconds
Each hour contains 3,600 seconds.
Multiply the hour value by 3,600.
Eight hours equal 28,800 seconds.
Minute and Decimal-Hour Conversion Chart
The following table converts common minute values into decimal hours and seconds.
| Minutes | Fraction of an hour | Decimal hours | Seconds |
|---|---|---|---|
| 5 | 1/12 | 0.0833 | 300 |
| 10 | 1/6 | 0.1667 | 600 |
| 15 | 1/4 | 0.25 | 900 |
| 20 | 1/3 | 0.3333 | 1,200 |
| 30 | 1/2 | 0.50 | 1,800 |
| 40 | 2/3 | 0.6667 | 2,400 |
| 45 | 3/4 | 0.75 | 2,700 |
| 50 | 5/6 | 0.8333 | 3,000 |
| 60 | 1 | 1.00 | 3,600 |
Hours and Minutes Conversion Chart
This table compares common elapsed durations in several forms.
| Hours and minutes | Total minutes | Decimal hours | Total seconds |
|---|---|---|---|
| 1h 15m | 75 | 1.25 | 4,500 |
| 1h 30m | 90 | 1.50 | 5,400 |
| 1h 45m | 105 | 1.75 | 6,300 |
| 2h | 120 | 2.00 | 7,200 |
| 2h 30m | 150 | 2.50 | 9,000 |
| 4h | 240 | 4.00 | 14,400 |
| 7h 30m | 450 | 7.50 | 27,000 |
| 8h | 480 | 8.00 | 28,800 |
| 8h 30m | 510 | 8.50 | 30,600 |
Using the Chart for Work Hours
Convert break-adjusted work time into decimal hours for payroll or reporting.
For example, seven hours 30 minutes equal 7.5 decimal hours.
The Time Duration Calculator displays the conversion automatically.
Using the Chart for Billing
Time-based billing often requires a decimal-hour value.
Fifteen minutes equal 0.25 hours, while 45 minutes equal 0.75 hours.
Multiply the decimal duration by the applicable hourly rate.
Repeating Decimal Values
Some minute values do not convert to terminating decimals.
Twenty minutes equal 0.3333 continuously, while 40 minutes equal 0.6666 continuously.
Round the final result according to the required level of precision.
Thirty minutes equal 0.5 hours, not 0.30 hours.
Common Mistakes
Do not divide minutes by 100 when converting to decimal hours.
Do not write 45 minutes as 0.45 hours.
Remember that each hour contains 3,600 seconds.
Avoid rounding repeating decimals before completing later calculations.
Conclusion
Use multiplication to move from larger time units to smaller units and division to move in the opposite direction.
The charts provide quick references for common durations.
Use the Time Duration Calculator for elapsed values not listed.
FAQs
How many minutes are in one hour?
There are 60 minutes in one hour.
How many seconds are in one hour?
There are 3,600 seconds in one hour.
What is 30 minutes in decimal hours?
Thirty minutes equal 0.5 hours.
What is 45 minutes in decimal hours?
Forty-five minutes equal 0.75 hours.
How many minutes are in 8 hours 30 minutes?
Eight hours 30 minutes equal 510 minutes.