Convert seconds to milliseconds
Enter a value in seconds to convert it to milliseconds.
seconds to milliseconds reference
| seconds | milliseconds |
|---|---|
| 1 s | 1000 ms |
| 2 s | 2000 ms |
| 5 s | 5000 ms |
| 10 s | 10000 ms |
| 25 s | 25000 ms |
| 50 s | 50000 ms |
| 100 s | 100000 ms |
The conversion factor
One second is 1000 milliseconds. So to convert, multiply your figure in seconds by 1000. To go the other way, multiply milliseconds by 0.001, or use the milliseconds to seconds converter.
Doing it in your head
For a quick estimate, round the factor: roughly "times 1000". Use the exact converter above when the number matters.
Where this conversion comes up
Durations in code and spreadsheets, timeouts, and project estimates.
See the common unit conversions cheat sheet for the factors worth memorising.
Related tools
Frequently asked questions
How many milliseconds are in a second?
1 second = 1000 milliseconds.
What is the formula to convert seconds to milliseconds?
Multiply the number of seconds by 1000. To go back the other way, multiply milliseconds by 0.001.
What is 10 seconds in milliseconds?
10 seconds = 10000 milliseconds. The reference table below lists more common values.
Is this converter accurate?
It uses the internationally defined conversion factors and computes at full floating-point precision, then rounds only the displayed result. For everyday purposes it is exact; for legal, engineering or scientific work, confirm the required number of significant figures.
Does it work offline?
Yes. The conversion runs in your browser with no server call, so it keeps working with no connection, and nothing you enter is uploaded.
Last reviewed: September 2026. Figures and formulas are checked against their published sources; see the site's data notes.