The femtosecond conversion selector on this page selects the time measurement unit to convert to starting from femtoseconds (fs). To make a conversion starting from a unit of time other than femtosecond, simply click on the "Reset" button.
The femtosecond is a unit of time in the metric system equal to one quadrillionth of a second (1 fs = 10-15 s).
One femtosecond (fs) is also equal to 1,000 attoseconds (as), or 10-6 nanoseconds (ns), or 10-9 microseconds (μs) or 10-12 milliseconds (ms), which are SI units of time.
Times of this magnitude (i.e., on the femtosecond time scale) are commonly used in science for molecular dynamics simulations, and in laser physics and technology.