Convert seconds to milliseconds
Convert seconds to milliseconds instantly. 1 s = 1,000 ms. Formula, worked examples and a quick reference table.
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One second equals 1,000 milliseconds. To convert any number of seconds to milliseconds, multiply by 1,000.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Time conversions are exact down to the day and approximate above it. Seconds, minutes, hours and days have fixed ratios, but a month has no fixed length and a year has two — 365 days in the calendar and 365.25 in the astronomical convention used here. For anything with legal or contractual weight, count the actual calendar dates rather than converting a duration, because the difference accumulates precisely where it is least welcome.
seconds to milliseconds formula
To go the other way, use second = millisecond ÷ 1,000.
About these units
The second is defined by the caesium atom: 9,192,631,770 oscillations of a particular transition. Every other time unit is now derived from it.
A millisecond is a thousandth of a second. It is the unit of network latency and of video frame timing, where a difference of twenty is visible.
Second is also written seconds, sec and secs. Millisecond is also written milliseconds and msec.
Sources
seconds to milliseconds conversion table
| Second | Millisecond |
|---|---|
| 1 s | 1,000 ms |
| 2 s | 2,000 ms |
| 3 s | 3,000 ms |
| 5 s | 5,000 ms |
| 10 s | 10,000 ms |
| 20 s | 20,000 ms |
| 25 s | 25,000 ms |
| 50 s | 50,000 ms |
| 100 s | 100,000 ms |
| 250 s | 250,000 ms |
| 500 s | 500,000 ms |
| 1,000 s | 1,000,000 ms |
Frequently asked questions
How many milliseconds are in a second? +
There are 1,000 milliseconds in one second.
What is 10 s in ms? +
10 s equals 10,000 ms. Multiply 10 by 1,000.
How do I convert millisecond back to second? +
Use second = millisecond ÷ 1,000. The converter above handles both directions, or see our dedicated milliseconds to seconds page.
How accurate is this second to millisecond conversion? +
The factor used is 1,000, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate s to ms in my head? +
Multiply by 1,000. That matches the true factor of 1,000 exactly, so no adjustment is needed for a mental estimate.