CONDUIT BENDING
CONDUIT BENDING
shrink = offset × (cosec − cot)
in
RESULT
—
FILL IN ABOVE
Offset multipliers: 22.5°→2.6, 30°→2.0, 45°→1.4, 60°→1.15. Shrink per inch of rise: 22.5°→3/16", 30°→1/4", 45°→3/8", 60°→1/2". Estimate only — confirm against your bender's deduct and verify with a licensed electrician before installation.
About this calculator
This conduit bending calculator handles the two bends every electrician runs daily: the offset (two opposite bends to step a run around an obstruction) and the 3-bend saddle (center bend at 2× the side bends to clear an obstacle in the middle of a run). Pick the bend angle and rise/obstacle height — the calculator returns the distance between marks, the shrink (how much the run loses to the bends), and where to start the first mark from a known reference. Multipliers come from the standard bender table: 22.5° → 2.6, 30° → 2.0, 45° → 1.4, 60° → 1.15. ESTIMATE ONLY — final layout must be verified against the actual bender deduct/take-up and AHJ requirements.
Common questions
What is shrink and why does it matter?
When you bend an offset, the conduit gets shorter overall by a small amount per inch of rise — the "shrink." If you cut and thread before bending, you have to start your first mark farther from the box by exactly that amount or your conduit will land short. 30° offsets shrink ¼" per inch of rise; 45° offsets shrink 3⁄8" per inch.
Why do offset multipliers exist?
They convert the rise (vertical step you need) into the distance between the two bend marks on the pipe. 30° = 2.0 (mark-to-mark = 2× rise); 45° = 1.4; 22.5° = 2.6. Without the multiplier you would have to do trig on the job — benders that print these on the handle (Klein, Greenlee) save the math.
How does a 3-bend saddle differ from an offset?
An offset uses two opposite bends to step around an obstacle that is at the side of the run; a saddle uses three bends (center bend at 2× the side angles) to lift over an obstacle that crosses the middle of the run — typically another conduit or a beam. The center bend goes over the obstacle, the two outer bends bring the pipe back to its original line.