Look up nanosecond in Wiktionary, the free dictionary.

A nanosecond (ns) is a unit of time in the International System of Units (SI) equal to one billionth of a second, that is, 1⁄1 000 000 000 of a second, or 10⁻⁹ seconds.

The term combines the SI prefix nano- indicating a 1 billionth submultiple of an SI unit (e.g. nanogram, nanometre, etc.) and second, the primary unit of time in the SI.

A nanosecond is equal to 1000 picoseconds or 1⁄1000 microsecond. Time units ranging between 10⁻⁸ and 10⁻⁷ seconds are typically expressed as tens or hundreds of nanoseconds.

Time units of this granularity are commonly found in telecommunications, pulsed lasers, and related aspects of electronics.

Common measurements

• 0.001 nanoseconds – one picosecond
• 0.96 nanoseconds – 100 Gigabit Ethernet Interpacket gap
• 1.0 nanosecond – cycle time of an electromagnetic wave with a frequency of 1 GHz (1×10⁹ hertz).
• 1.0 nanosecond – electromagnetic wavelength of 1 light-nanosecond. Equivalent to 0.3m radio band.
• 1.016703362164 nanoseconds (by definition) – time taken by light to travel 1 foot in a vacuum.^{[n 1]}
• 3.3356409519815 nanoseconds (by definition) – time taken by light to travel 1 metre in a vacuum.^[1]
• 8 nanoseconds - typical propagation delay of 74HC series logic chips based on HCMOS technology, commonly used for digital electronics in the mid-1980s.^[2]
• 10 nanoseconds – one "shake", (as in a "shake of a lamb's tail") approximate time of one generation of a nuclear chain reaction with fast neutrons
• 10 nanoseconds – cycle time for frequency 100 MHz (1×10⁸ hertz), radio wavelength 3 m (VHF, FM band)
• 10 nanoseconds – half-life of lithium-12
• 12 nanoseconds – mean lifetime of a charged K meson^[3]
• 20–40 nanoseconds – time of fusion reaction in a hydrogen bomb
• 30 nanoseconds – half-life of carbon-21
• 77 nanoseconds – a sixth (a 60th of a 60th of a 60th of a 60th of a second)
• 96 nanoseconds – Gigabit Ethernet Interpacket gap
• 100 nanoseconds – cycle time for frequency 10 MHz, radio wavelength 30 m (shortwave)
• 299 nanoseconds – half-life of polonium-212
• 333 nanoseconds – cycle time of highest medium wave radio frequency, 3 MHz
• 500 nanoseconds – T1 time of Josephson phase qubit (see also Qubit) as of May 2005
• 1,000 nanoseconds – one microsecond