What is microsecond?

A microsecond is a unit of time equal to one millionth of a second. It is used in electronics, radar systems, telecommunications, and measuring the speed of high-frequency processes.

Real-world uses

Microseconds are used to measure CPU instruction execution times, radar pulse durations, and ultrasonic echo intervals. High-frequency trading systems operate on microsecond timescales, and camera flash durations are typically 1–1,000 µs.

History

The microsecond became measurable with the development of oscilloscopes and electronic timing circuits in the early 20th century. The prefix "micro-" was adopted from Greek and formally standardized as an SI prefix in 1960.

Common mistakes

Using "us" instead of "µs" as the symbol, which can cause confusion with the word "us" in text. Also, conflating microseconds with milliseconds in performance benchmarks, leading to 1000x reporting errors.

What is millisecond?

A millisecond is a unit of time equal to one thousandth of a second. It is used in computing, networking, audio and video processing, and measuring reaction times and signal latencies.

Real-world uses

Milliseconds are critical in computing for measuring network latency (ping times), database query performance, and real-time system response. Financial trading platforms measure order execution in milliseconds, and human reaction time averages about 250 ms.

History

The millisecond became a practical unit with the invention of precise mechanical chronographs in the 19th century. Its importance exploded with electronic computing, where operations occur in millisecond and sub-millisecond timescales.

Common mistakes

Confusing milliseconds with microseconds in performance profiling—they differ by a factor of 1,000. Also, assuming human perception cannot detect millisecond differences, when in fact audio delays above 10 ms are perceptible.

When is this conversion used?

Converting microsecond to millisecond is useful in the time domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 microsecond = 0.001 millisecond

1 millisecond = 0.001 second

How to convert microsecond to millisecond

To convert microsecond to millisecond, multiply the value by 0.001.

To convert millisecond back to microsecond, multiply by 1,000.

Measurement standards

The SI second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom, maintained by the BIPM and national metrology institutes worldwide.

Did you know?

Earth's rotation is gradually slowing due to tidal friction with the Moon. To keep atomic time aligned with solar time, "leap seconds" have been inserted 27 times since 1972 — though they are scheduled to be abolished by 2035.

Quick reference: microsecond to millisecond

microsecondmillisecond
0.10.0001
0.50.0005
10.001
20.002
50.005
100.01
250.025
500.05
1000.1
2500.25
5000.5
1,0001

Common values

microsecondmillisecond
Blink of an eye300,000 microsecond300 millisecond
Average pop song210,000,000 microsecond210,000 millisecond
Feature film7.200000e+09 microsecond7,200,000 millisecond
One work day (8 hrs)2.880000e+10 microsecond28,800,000 millisecond
One calendar year3.153600e+13 microsecond3.153600e+10 millisecond