Horizontal logarithmic scale marked with units of time

A millisecond (from milli- and second; symbol: ms) is a unit of time in the International System of Units ( The International System of Units AKA ''SI'' is a system that classes different types of units: Time, Weight, Length and various other units) equal to one thousandth (0.001 or 10−3 or 1/1000) of a second[1][2] and to 1000 microseconds.

A unit of 10 milliseconds may be called a centisecond, and one of 100 milliseconds a decisecond, but these names are rarely used.[3] To help compare orders of magnitude of different times, this page lists times between 10−3 seconds and 100 seconds (1 millisecond and one second). See also times of other orders of magnitude.


The Apollo Guidance Computer used metric units internally, with centiseconds used for time calculation and measurement.[4]

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See also


  1. ^ "Units: M". How Many? A Dictionary of Units of Measurement.
  2. ^ New Oxford Dictionary
  3. ^ Google nGrams shows them as much less than 0.5% of "millisecond" nGrams comparison of word frequency of centisecond and decisecond vs. millisecond
  4. ^ "The Moon landings". UK Metric Association. 2018-10-18. Retrieved 2021-03-03.
  5. ^ "Seamless Gearbox".
  6. ^ "Blink and you miss it". 2005-08-03.