Convert Hours to Seconds
Hours to seconds is the conversion you reach for when you need the finest level of detail — timing an event, setting a countdown, or feeding a duration into a calculation that expects seconds. One hour is exactly 3600 seconds, so the number always gets much bigger when you switch from hours to seconds.
Hours to Seconds conversion table
| Hours (h) | Seconds (s) |
|---|---|
| 1 | 3,600 |
| 2 | 7,200 |
| 3 | 10,800 |
| 5 | 18,000 |
| 10 | 36,000 |
| 20 | 72,000 |
| 50 | 180,000 |
| 100 | 360,000 |
| 500 | 1,800,000 |
| 1,000 | 3,600,000 |
The formula
To convert hours to seconds, multiply the duration in hours by 3600:
seconds = hours × 3600
A worked example
Say you want to convert a 2-hour movie into seconds:
2 × 3600 = 7200 seconds
That's how many seconds tick by during those two hours.
Why the number is exact
An hour is defined as exactly 60 minutes, and a minute is defined as exactly 60 seconds. Multiply those together and you get 3600 seconds in every hour, with nothing approximate about it — the relationship is a fixed definition, not a measurement.
When you'll use it
Setting timers or countdowns, timing events for scripts and video edits, and converting durations for anything that measures time in raw seconds, like some programming and scientific tools.
Frequently asked questions
How many seconds are in an hour?
Exactly 3600 seconds. An hour is defined as 60 minutes, and each minute is defined as 60 seconds, so 60 × 60 = 3600 with no rounding involved.
Is the hours to seconds conversion exact?
Yes. Hours and seconds are both defined in terms of the same fixed relationship — 3600 seconds per hour — so multiplying by 3600 gives an exact answer every time.
What's a quick way to estimate hours in seconds?
Multiply by 3600, or think of it as 60 minutes of 60 seconds each. Half an hour is 1800 seconds; a quarter hour is 900 seconds.