Full name: femtometre
Plural form: femtometers
Symbol: fm
Alternate spelling: femtometres
Category type: length
Scale factor: 1.0E-15
The SI base unit for length is the metre.
1 metre is equal to 1.0E+15 femtometer.
Valid units must be of the length type.
You can use this form to select from known units:
The SI prefix "femto" represents a factor of 10-15, or in exponential notation, 1E-15.
So 1 femtometre = 10-15 metre.