What this calculator does
Hours to seconds is a two-step conversion in disguise: an hour is 60 minutes, and each of those minutes is 60 seconds, so one hour comes to 3,600 seconds. That figure is worth memorising, because it turns up constantly when a duration quoted in hours needs entering into a system, script or stopwatch that only counts in seconds.
This calculator converts hours to seconds or seconds to hours, both directions, and shows the equivalent in minutes as well. It also answers how many seconds in an hour directly: exactly 3,600, every time, since an hour is a fixed unit with no leap-second-style irregularity to account for.
The formula
An hour is defined as exactly 3,600 seconds (60 minutes of 60 seconds each), so converting hours to seconds means multiplying by 3,600, and converting seconds to hours means dividing by 3,600. Both directions are exact, with no rounding built into the factor itself.
| Term | Meaning |
|---|---|
| Hour | A unit of time equal to 3,600 seconds, or 60 minutes. |
| Second | The base SI unit of time; 3,600 seconds make one hour. |
| 3,600 | The exact, fixed number of seconds in an hour, used in both directions of this conversion. |
The inputs explained
| Field | What to enter |
|---|---|
| Value | The value to convert, either a number of hours or a number of seconds, depending on the direction chosen below. |
| Convert | Choose whether to convert hours to seconds, or seconds to hours. |
When to use it
Setting a duration in a script or system
Many timers, schedulers and APIs take a duration in seconds even when the natural unit to think in is hours, so converting before entering the figure avoids an off-by-a-large-factor mistake.
Making sense of a large seconds figure
A duration reported only in seconds, such as 86,400 seconds for a full day, converts to hours for an easier sense of how long it actually is.
Comparing durations quoted inconsistently
Two durations, one in hours and one in seconds, convert to the same unit before they can be compared directly.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Hours to seconds, for common durations
A range of hour values, each converted to seconds and minutes.
| Hours | Seconds | In minutes |
|---|---|---|
| 1 | 3,600 s | 60.00 min |
| 2 | 7,200 s | 120.00 min |
| 4 | 14,400 s | 240.00 min |
| 8 | 28,800 s | 480.00 min |
| 12 | 43,200 s | 720.00 min |
| 24 | 86,400 s | 1,440.00 min |
Seconds to hours, for common durations
A range of second values, each converted to hours.
| Seconds | Hours | In minutes |
|---|---|---|
| 3600 | 1.000 hr | 60.00 min |
| 7200 | 2.000 hr | 120.00 min |
| 36000 | 10.000 hr | 600.00 min |
| 86400 | 24.000 hr | 1,440.00 min |
| 100000 | 27.778 hr | 1,666.67 min |
| 500000 | 138.889 hr | 8,333.33 min |
Questions
How many seconds in an hour?
Exactly 3,600 seconds, from 60 minutes multiplied by 60 seconds per minute. This is a fixed figure with no rounding.
How many seconds is 4 hours?
Exactly 14,400 seconds, from 4 × 3,600.
How many hours is 86,400 seconds?
Exactly 24 hours, from 86,400 ÷ 3,600, which is also why 86,400 seconds is the length of a standard day.
Is the conversion between hours and seconds ever approximate?
No. An hour is defined as exactly 3,600 seconds, so converting in either direction is exact, provided the input value itself is exact.
For a duration in minutes rather than hours, see the minutes to seconds converter. For very long durations across a whole year, see the seconds in a year calculator.