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.

What is nanosecond?

A nanosecond is a unit of time equal to one billionth of a second. It is critical in computer processor timing, high-frequency trading, optical communications, and physics experiments.

Real-world uses

Nanoseconds are used in computing to measure memory access times (DRAM latency is typically 10–100 ns), CPU cache operations, and network packet timestamps. Light travels approximately 30 cm in one nanosecond, a fact used in signal timing.

History

The nanosecond became a practical unit with the advent of digital electronics in the 1960s. Grace Hopper famously used a 30 cm piece of wire to demonstrate the distance light travels in a nanosecond, making the concept tangible for non-engineers.

Common mistakes

Underestimating how short a nanosecond is—light only travels about one foot in a nanosecond. Also, confusing nanoseconds with microseconds in performance specifications, which differ by a factor of 1,000.

When is this conversion used?

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

Worked examples

1 millisecond = 1,000,000 nanosecond

1 nanosecond = 1.000000e-09 second

How to convert millisecond to nanosecond

To convert millisecond to nanosecond, multiply the value by 1,000,000.

To convert nanosecond back to millisecond, multiply by 0.000001.

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: millisecond to nanosecond

millisecondnanosecond
0.1100,000
0.5500,000
11,000,000
22,000,000
55,000,000
1010,000,000
2525,000,000
5050,000,000
100100,000,000
250249,999,999.99999997
500499,999,999.99999994
1,000999,999,999.99999988

Common values

millisecondnanosecond
Blink of an eye300 millisecond300,000,000 nanosecond
Average pop song210,000 millisecond2.100000e+11 nanosecond
Feature film7,200,000 millisecond7.200000e+12 nanosecond
One work day (8 hrs)28,800,000 millisecond2.880000e+13 nanosecond
One calendar year3.153600e+10 millisecond3.153600e+16 nanosecond