Arrowmark › Offset calculator
Conduit offset calculator
Enter how far the conduit has to jog (the rise) and the bend angle. You get the distance between the two bends and how much the run shrinks, ready to read off a tape.
Multiplier method: it ignores the bender's radius, so real marks for your shoe land slightly closer together.
Common offsets
| Rise | Angle | Between bends | Shrink |
|---|---|---|---|
| 4" | 22.5° | 10 7/16" | 13/16" |
| 6" | 30° | 12" | 1 5/8" |
| 8" | 30° | 16" | 2 1/8" |
| 10" | 45° | 14 1/8" | 4 1/8" |
| 12" | 45° | 17" | 5" |
How the offset math works
Distance between bends = rise × multiplier, where the multiplier is 1 ÷ sin(angle): 2 for 30°, 1.414 for 45°, 2.613 for 22.5°. Shrink = rise × tan(angle ÷ 2) — the length of conduit the offset uses up, so add it to the measurement to the obstruction when you place the first mark. The full table is on the offset multiplier chart.
On the job, the bender changes the answer. This calculator uses the multiplier method, like most charts. Arrowmark uses the radius and deduct of the bender you pick — Greenlee, Klein, Ideal, Gardner, Milwaukee and more — plus rolling, parallel and matching offsets, saddles, kicks and 90s, a step-by-step guide, and voice input: say “rise 6 at 30” and the marks are there.