How the cut length is worked out
The travel is measured centre to centre of the two fittings, but the fittings themselves take up part of that distance. That part is each fitting's take-out. Subtract both take-outs, and the gap at each joint, and you have the length of pipe to cut.
cut = travel − (take-out A + gap) − (take-out B + gap)
Example: 26" travel between two 2" long-radius butt-weld 90° elbows. Each elbow takes out 3", with a 1/16" root gap at each joint. 26 − 3 1/16 − 3 1/16 = 19 7/8".
Why this page asks you for the take-outs
Take-outs change with the pipe size, the fitting (90°, 45°, tee, long or short radius) and the joint (butt weld, socket weld, threaded, copper, PVC, press, grooved). A wrong one ruins the cut, so this page doesn't guess. It will not give you an answer until both ends are filled in.
Don't have the take-outs? CutRight looks them up for you, with no signal.
This free page needs you to know both take-outs, and it only works with a connection. The CutRight app has the take-outs from the published fitting tables for the common sizes, fittings and joints, works each end out on its own, and works fully offline. Pay once, no subscription.