Calculate cut lengths for pipes based on center-to-center dimensions and fitting take-offs.
Pipe takeoff is the dimension subtracted from a center-to-center measurement to find the actual cut length of straight pipe between two fittings. Every welded, threaded, or grooved fitting consumes length where the pipe insertion or socket overlap occurs, so accurate takeoff values are essential for spool-piece fabrication, isometric drawings, and material lists. This calculator returns cut length from c-c distance, fitting type, and size.
Cut length L = D_cc − T_fitting_1 − T_fitting_2 where D_cc is the center-to-center distance and T is each fitting's takeoff value. Takeoff varies by fitting type and standard: a 90° long-radius elbow in Schedule 40 carbon steel has a takeoff equal to 1.5 × nominal pipe size for the centerline-to-face dimension. A short-radius 90° is 1.0 × NPS, a 45° elbow is 0.625 × NPS, and a tee branch is also 1.5 × NPS. For threaded fittings, subtract the make-up distance (typically 1/2 of nominal size) per joint. The calculator supports inch and millimeter input, NPS and DN sizing, and reports cut length in the same unit as the c-c input. Always add a small allowance (3–5 mm) per cut for grinding and bevelling unless the procedure specifies field-fit.
A pipe fitter cutting carbon-steel spool pieces between two 4-inch long-radius 90° elbows on a 60-inch c-c run subtracts two 6-inch takeoffs and cuts the pipe to 48 inches before bevelling, knowing the elbow geometry will restore the design dimension.
A piping detailer converting an isometric drawing to a fabrication cut list applies the takeoff table for 2-inch Schedule 80 elbows and tees, generating a material take-off (MTO) and cut sheet for the shop within minutes instead of manual lookups.
A field welder discovering a 6-inch socket-weld elbow with a different takeoff than the standard catalog recalculates cut length on the spot and trims 12 mm to keep the run square to the structural steel reference line.
Fitting takeoff dimensions are published in ASME B16.9 for welded fittings, ASME B16.11 for forged threaded/socket-weld fittings, and ASME B16.5 for flanged fittings. Manufacturer catalogs also include them.
Yes. Long-radius (LR) 90° elbow takeoff is 1.5 × NPS, short-radius (SR) 90° is 1.0 × NPS. The catalog drawing always specifies the centerline-to-face dimension.
Welded fittings consume the full takeoff dimension. Threaded fittings also consume make-up distance — usually 1/2 of nominal size per joint — which must be subtracted in addition.