Milliseconds to Seconds (ms to s)
1 millisecond equals 0.001 seconds exactly.
How to convert milliseconds to seconds
To convert milliseconds to seconds, multiply the number of milliseconds by 0.001. This factor is exact. To go the other way, multiply seconds by 1,000.
seconds = milliseconds × 0.001
Example: 10 milliseconds = 0.01 seconds.
Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.
About these units
Millisecond (ms)
One thousandth of a second. Used for computer response times and sports timing.
Milliseconds sit on the border between what people perceive and what instruments must be built to catch. Nobody feels a single one: a human blink lasts roughly 100 to 400 of them, and the average resting heart cycle is about 860. The prefix milli- makes the unit exactly one thousandth of a second, so it is a handy yardstick for events a little too quick to notice but slow enough for a stopwatch-style instrument to capture.
A millisecond is one thousandth of a second, and the scale references are easy to picture. Light in a vacuum covers about 300 km in 1 ms, and sound in air covers about 34 cm. A film frame at 24 frames per second lasts about 41.7 ms, one cycle of 60 Hz mains power lasts about 16.7 ms, and a camera shutter set to 1/125 s is open for about 8 ms. Online gamers watch network latency in milliseconds, with typical broadband figures of 5 to 80 ms, and telephone engineers recommend keeping one-way delay under about 150 ms before conversation starts to feel awkward.
1 millisecond = 0.001 seconds (exactly).
Sources: Wikipedia: Millisecond; BIPM: SI Brochure, 9th edition
Second (s)
The SI base unit of time, defined by the radiation frequency of the cesium-133 atom: 9,192,631,770 cycles per second.
Our word second is a leftover of Latin. Medieval scholars divided a degree, and later the hour, into 60 parts called pars minuta prima, the first small part, and divided those again into pars minuta secunda, the second small part. NIST traces the roots further back: Babylonian and Greek astronomers split the circle into 360 degrees, and around 150 C.E. Ptolemy split each degree into 60 minutes and each minute into 60 seconds. Clocks that could show seconds appeared only in the later 16th century, and Christiaan Huygens's pendulum clock of 1656 was the first able to keep time accurately to the second.
For most of history the second was a fraction of a day, and in 1956 it was redefined as a fraction of the tropical year, a definition the SI took over in 1960. In 1967 the 13th CGPM switched to atoms: 9,192,631,770 periods of the radiation tied to a hyperfine transition of caesium-133. The 2019 SI revision restated this by fixing the caesium frequency at 9,192,631,770 hertz. NIST reports that commercial caesium clocks stay within about a three-millionth of a second per year, and experimental clocks based on other atoms are roughly ten thousand times more precise.
The second is the reference unit for time on this site.
Sources: NIST: the second and the SI redefinition; BIPM: SI Brochure, 9th edition; Wikipedia: Second
Related conversions
- Seconds to milliseconds (reverse)
- Milliseconds to minutes
- Milliseconds to hours
- Milliseconds to days
- Milliseconds to weeks
- Milliseconds to months
- Milliseconds to years
- Milliseconds to microseconds
- Milliseconds to nanoseconds
- Milliseconds to decades
- Milliseconds to centuries
- Milliseconds to millennia
- Minutes to seconds
- Hours to seconds
- Days to seconds
- Weeks to seconds
- Months to seconds
- Years to seconds
- Microseconds to seconds
- Nanoseconds to seconds
- Decades to seconds
- Centuries to seconds
- Millennia to seconds
- Picoseconds to seconds
See all time units.