I would use feet
By unit of length and distance and conversion ,we can say that the most appropriate unit to measure the length of a finger is cm.
Inches
cm
always the meter to measure length. This is an SI (international) unit of measurment, and is the standard international unit of measurment for length.
You would use meters.
yards
feet
miles or kilomiters
inch
miles
A metres, for an approximate measure, a centimetre for a more accurate measure.
Centimetres.