Capacities In Feet Of Rope = (A + B) ACK
Example:

How much 1 1/4" diameter rope can be spooled on a drum having a 36" diameter flange, 24" diameter drum and 30" width between flanges?

Using the above formula the number of feet equals
(6 + 24) x 6 x 30 x .152 or (A + B) x A x C x K
Answer - 821 feet

The value of "K" is taken from the previously calculated table of values shown below. For 1 1/4 diameter this value "K" is .152

* This formula is based on uniform rope winding on the reel. It will not give correct results if the winding is non-uniform. The formula also assumes that there will be the same number of wraps in each layer. While this is not strictly correct, there is no appreciable error in the result unless the traverse of the reel is quite small relative to the flange diameter ("H").

** The values given for "K" factors take normal rope oversize into account.