Milliseconds to Days
Type a value in either box to convert between milliseconds and days. The factor is 1.15741e-08.
| Milliseconds | Days |
|---|---|
| 1 ms | 1.15741e-08 day |
| 2 ms | 2.31481e-08 day |
| 3 ms | 3.47222e-08 day |
| 5 ms | 5.78704e-08 day |
| 10 ms | 1.15741e-07 day |
| 25 ms | 2.89352e-07 day |
| 50 ms | 5.78704e-07 day |
| 100 ms | 1.15741e-06 day |
How to use
- Enter a value in the Milliseconds field.
- The Days figure appears immediately — no button to press.
- Typing in the Days field converts back to Milliseconds the same way.
- Use the reference table for the values that come up most often.
Milliseconds to Days formula
Converting milliseconds to days is a single multiplication by 1.15740741e-08.
day = ms × 1.15740741e-08
Why this factor: the millisecond and the day are both defined against the second, so dividing one definition by the other gives 1.15740741e-08 directly. Both definitions are set out in full below.
To go the other way, divide by 1.15740741e-08 — or use the Days to Milliseconds converter, which is the same calculation reversed.
Worked example
Take 15 ms and multiply by the factor 1.15740741e-08: the result is 1.73611e-07 day.
15 ms × 1.15740741e-08 = 1.73611e-07 day
The converter above does this for any value you type, in either direction.
What is a millisecond?
A millisecond is one thousandth of a second, the unit of perceptible computing delay.
Definition: Exactly 0.001 second by SI prefix definition.
Where it is used: Network latency and ping times, audio buffer sizes, and animation and reaction timings.
What is a day?
A day is 24 hours, one nominal rotation of the Earth.
Definition: Exactly 86,400 seconds by convention. The Earth's actual rotation drifts slightly, which is what leap seconds correct.
Where it is used: Calendars, project schedules, hotel and rental periods, and interest accrual.
Milliseconds vs Days
The millisecond is a metric unit while the day is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many days are in a millisecond?
One millisecond equals 1.15740741e-08 days.
What is the formula to convert milliseconds to days?
Multiply the number of milliseconds by 1.15740741e-08. To reverse it, divide by 1.15740741e-08 instead.
How do I convert days back to milliseconds?
Divide by 1.15740741e-08, which is the same as multiplying by 86400000.
How many days are in 10 milliseconds?
10 ms works out to 1.15741e-07 day.
How is the millisecond defined?
Exactly 0.001 second by SI prefix definition.