Axis

Time & duration

femtosecondfs

Femto-scaled variant of the second, exactly fs = 0.000000000000001 base unit.

Dimension
time
Canonical signature
T
System
si
Exactness
Exact

Definition record

How this unit is defined

Canonical base
1 fs = 1e-15 s
Conversion type
linear
Historical notes
Defined from the caesium-133 hyperfine transition frequency (SI 2019).
Aliases
femto sec, femto seconds, femto secs

Same dimension

Related units

secondsisminutesi acceptedminhoursi acceptedhdaysi accepteddyear (Julian)astronomicalyrweeksi acceptedwkquettasecondsiQsronnasecondsiRs

Common conversions

Every conversion routes through the canonical base of the dimension.

1 fs = 1e-15 s

Exact relationship

10 fs = 1e-14 s

Exact relationship