How many hours are in a month?
There are 720 hours in a 30-day month, 744 in a 31-day month, and 730.485 on average.
A minute is 60 seconds, an hour 60 minutes and a day 24 hours, by NIST's table of units.
Show the workings
| Step | Sum | Answer |
|---|---|---|
| 30 days in seconds | 30 × 86,400 | 2,592,000 seconds |
| In hours | 2,592,000 ÷ 3,600 | 720 hours |
Where the figures come from
- Seconds in a minute: 60 seconds. Source: NIST Guide to the SI, section 5.1.1, Table 6: units accepted for use with the SI. Checked 14 November 2026.
- Minutes in an hour: 60 minutes. Source: NIST Guide to the SI, section 5.1.1, Table 6: units accepted for use with the SI. Checked 14 November 2026.
- Hours in a day: 24 hours. Source: NIST Guide to the SI, section 5.1.1, Table 6: units accepted for use with the SI. Checked 14 November 2026.
- A leap year comes every this many years: 4 years. Source: Calendar (New Style) Act 1750, section 2. Checked 14 November 2026.
- Hundredth years are common years, not leap years: 100 years. Source: Calendar (New Style) Act 1750, section 2. Checked 14 November 2026.
- Except every fourth hundredth year, which is a leap year: 400 years. Source: Calendar (New Style) Act 1750, section 2. Checked 14 November 2026.
- Days in a common year: 365 days. Source: Calendar (New Style) Act 1750, section 2. Checked 14 November 2026.
The sum
| In | Sum | Hours |
|---|---|---|
| A month of 28 days | 28 × 24 | 672 |
| A month of 29 days | 29 × 24 | 696 |
| A month of 30 days | 30 × 24 | 720 |
| A month of 31 days | 31 × 24 | 744 |
| The average month, 30.437 days | 365.2425 ÷ 12 × 24 | 730.485 |
Years and months are not all the same length. A year has 365 days, or 366 in a leap year. Over the calendar's 400-year cycle there are 97 leap years, so the average year is 365.2425 days and the average month is a twelfth of that. How leap years work.
Definitions from NIST Guide to the SI, section 5.1.1, Table 6: units accepted for use with the SI, checked 14 November 2026.
Other questions about time
- Seconds in a day
- Minutes in a day
- Seconds in an hour
- Hours in a week
- Minutes in a week
- Weeks in a month
- Hours in a year
- Minutes in a year
- Seconds in a year