Well bands are a mostly linear material. So the force applied by the band is approximated pretty well by:

F=k*x

F=force generated by the band

k=constant of elasticty (varies band to band)

x= displacement or (amount of stretch in the band)

The place where you bought bands should have some sort of rating for them (generally they would give the k constant). So something like k = 5lbs/in or something. Or it might be 60lbs/ft. Same diff. Or it could be metric.

Whatever the units, make sure you are using the same units of displacement.

Thats all I got for ya.


I-Dub