A day has 86,400 seconds: 24 hours × 60 minutes × 60 seconds. So 24 hours is 86,400 seconds, and a week is 604,800 seconds.
86,400 seconds
1 day = 86,400 seconds
| Unit | Amount |
|---|---|
| Milliseconds | 86,400,000 |
| Seconds | 86,400 |
| Minutes | 1,440 |
| Hours | 24 |
| Weeks | 0.1429 |
| Months | 0.0329 |
| Years | 0.0027 |
| Decades | 0.0002738 |
| Centuries | 0.00002738 |
How it’s calculated
Every unit is converted through seconds: 1 minute = 60 s, 1 hour = 3,600 s, 1 day = 86,400 s, 1 week = 604,800 s. Months and years use the Gregorian average: 1 year = 365.2425 days = 31,556,952 s, 1 month = 1/12 year = 2,629,746 s.
Worked example with your numbers
- 1 day × 86,400 seconds per day = 86,400 seconds.
- 86,400 seconds ÷ 1 seconds per second = 86,400 seconds.
Quick answer
A day has 86,400 seconds: 24 hours × 60 minutes × 60 seconds.
- 1 day (24 hours)
- 86,400 seconds
- 1 hour
- 3,600 seconds
- 1 week
- 604,800 seconds
- 1 year
- 31,536,000 seconds
| Unit | Seconds | Days | Years |
|---|---|---|---|
| 1 millisecond | 0.001 | 0.00000001157 | 0.000000000032 |
| 1 second | 1 | 0.00001157 | 0.00000003169 |
| 1 minute | 60 | 0.0006944 | 0.000001901 |
| 1 hour | 3,600 | 0.041667 | 0.0001141 |
| 1 day | 86,400 | 1 | 0.00273791 |
| 1 week | 604,800 | 7 | 0.01916535 |
| 1 month | 2,629,746 | 30.436875 | 0.08333333 |
| 1 year | 31,556,952 | 365.2425 | 1 |
| 1 decade | 315,569,520 | 3,652.425 | 10 |
| 1 century | 3,155,695,200 | 36,524.25 | 100 |
1 decade = 10 years; 1 century = 100 years; 1 millennium = 1,000 years. Months and years use the Gregorian average (365.2425 days a year).
How it works
On the days clocks change for daylight saving time, the local day is 23 or 25 hours long — 82,800 or 90,000 seconds. Leap seconds, added rarely to keep clocks in step with the Earth, are left out.
Frequently asked questions
How many seconds are in 24 hours?
86,400 seconds.
How many seconds are in an hour?
3,600 seconds.