Elkhunters formula gets the units correct.

Bullet weight (in grains) X Velocity (in Feet per second) Squared / 450240.

Same formula works for arrows and any projectile weighed in grains and measured in Feet per Second.

Example: 2700 fps x 2700 fps x 130gr / 450,240 =2105 ft/lb

Last edited by centershot; 02/27/20.
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