Hours to Seconds Converter
Convert hours to seconds instantly. One hour equals exactly 3,600 seconds. Type in either box to convert both ways, then use the chart, worked examples and everyday sizes below.
How to convert hours to seconds
Worked example: convert 90 hours to seconds. Using seconds ← hours × 3,600, we get 90 × 3,600 = 324,000 s. To check the result, convert back: 324,000 s ÷ 3,600 = 90 h.
Hours to seconds chart
| Hours (h) | Seconds (s) |
|---|---|
| 1 h | 3,600 s |
| 2 h | 7,200 s |
| 3 h | 10,800 s |
| 4 h | 14,400 s |
| 5 h | 18,000 s |
| 6 h | 21,600 s |
| 8 h | 28,800 s |
| 10 h | 36,000 s |
| 12 h | 43,200 s |
| 15 h | 54,000 s |
| 20 h | 72,000 s |
| 25 h | 90,000 s |
| 30 h | 108,000 s |
| 40 h | 144,000 s |
| 50 h | 180,000 s |
| 75 h | 270,000 s |
| 100 h | 360,000 s |
| 150 h | 540,000 s |
| 200 h | 720,000 s |
| 250 h | 900,000 s |
| 500 h | 1,800,000 s |
| 1,000 h | 3,600,000 s |
Seconds to hours (reverse)
| Seconds (s) | Hours (h) |
|---|---|
| 1 s | 0.0002777778 h |
| 2 s | 0.0005555556 h |
| 5 s | 0.001388889 h |
| 10 s | 0.002777778 h |
| 20 s | 0.005555556 h |
| 50 s | 0.01388889 h |
| 100 s | 0.02777778 h |
| 250 s | 0.06944444 h |
| 500 s | 0.1388889 h |
| 1,000 s | 0.2777778 h |
About the hour and the second
An hour is 60 minutes or 3,600 seconds. Working time, travel time, billing and battery capacity (watt-hours) use hours.
The second is the SI base unit of time, defined from the radiation of a caesium-133 atom (9,192,631,770 cycles). Stopwatches, video timestamps and speeds use it.
One hour is 3,600 times the size of one second, so it takes fewer hours than seconds to express the same amount.
Everyday sizes in hours and seconds
| Everyday example (approximate) | In hours | In seconds |
|---|---|---|
| A TV advert | 0.0083333 h | 30 s |
| A pop song | 0.058333 h | 210 s |
| A lecture | 0.83333 h | 3,000 s |
| A feature film | 2 h | 7,200 s |
| A working day | 8 h | 28,800 s |
| A long-haul flight | 10 h | 36,000 s |
Hours to seconds FAQ
How many seconds are in one hour?
One hour equals exactly 3,600 seconds. In the other direction, one second equals 0.00027777778 hours.
How do I convert hours to seconds without a calculator?
convert 90 hours to seconds. Using seconds ← hours × 3,600, we get 90 × 3,600 = 324,000 s. To check the result, convert back: 324,000 s ÷ 3,600 = 90 h. For a quick estimate, round the factor to 3,600. Then 90 h is about 324,000 s, compared with the exact 324,000 s (an error of 0%). That is close enough for planning, but use the calculator above when the number matters.
What is a lecture in seconds?
A lecture is about 0.83333 hours, which is 3,000 seconds. Treat that as an approximate everyday figure rather than an official measurement.
Are the hours and seconds the same in every country?
An hour is exactly 3,600 seconds in civil time. The second is defined by atomic clocks, so it is the same everywhere.