Offset bend calculator
Enter how far you need to move the conduit and the bend angle. You get the distance between your two marks and how much the offset shrinks the run.
Trade math for EMT benders · Free, no sign-up · Updated October 2026
Conduit offset multipliers by angle
Distance between bends = offset depth × multiplier. The multiplier is 1 ÷ sin(angle).
| Bend angle | Multiplier |
|---|---|
| 5° | 11.47 |
| 10° | 5.76 |
| 15° | 3.86 |
| 20° | 2.92 |
| 22.5° | 2.61 |
| 30° | 2.00 |
| 45° | 1.41 |
| 60° | 1.15 |
The calculator below covers 10, 22.5, 30, 45, and 60 degrees.
Result
12.00 in. between bends · shrink 1.61 in.
How it was calculated
- distance between bends = rise / sin(30°) = 6 / 0.5 = 12 in.
- shrink = rise × tan(30° / 2) = 6 × 0.2679 = 1.61 in.
- Add the shrink to your overall conduit length so the run lands at the target.
Assumptions
- 30° offset bender markings on both bends.
- Measurements are center-of-bend to center-of-bend.
- Shop rule-of-thumb shrink for 30°: 1/4 in. per inch of rise.
Basis
This is trade math, not an NEC rule. Check the marks on your own bender before you bend.
Offset multipliers and shrink
The distance between bends is the offset depth times the multiplier for your angle. The multiplier is 1 ÷ sin(angle), the cosecant.
- 10°: multiplier 5.76, shrink about 1/16 in. per inch of offset.
- 15°: multiplier 3.86, shrink about 1/8 in. per inch.
- 20°: multiplier 2.92, shrink about 3/16 in. per inch.
- 22.5°: multiplier 2.61, shrink about 3/16 in. per inch.
- 30°: multiplier 2.00, shrink about 1/4 in. per inch.
- 45°: multiplier 1.41, shrink about 3/8 in. per inch.
- 60°: multiplier 1.15, shrink about 1/2 in. per inch.
The calculator uses the exact trigonometry, so its numbers are slightly more precise than the shop fractions.
How to lay out an offset
- Measure to the obstruction and add the shrink. That is your first mark when you work toward the obstruction.
- Make the second mark at the distance between bends from the first.
- Bend the first mark to the angle, then roll the conduit 180° and bend the second mark to the same angle.
- Sight down the conduit to make sure both bends are in the same plane, or you'll get a dog leg.
Picking the angle
30° is the everyday choice: the multiplier is an easy 2, and the shrink is small. Use 10° or 22.5° for shallow offsets and long, easy pulls. Use 45° when you need to get over something in a short space. Steeper bends make pulling harder and count more against the 360° limit between pull points.
Need every multiplier and take-up in one place? Open the conduit bending cheat sheet.
Worked example
A 6 in. offset with 30° bends:
- Rise (in.): 6
- Bend angle: 30°
Result
12.00 in. between bends · shrink 1.61 in.
How it was calculated
- distance between bends = rise / sin(30°) = 6 / 0.5 = 12 in.
- shrink = rise × tan(30° / 2) = 6 × 0.2679 = 1.61 in.
- Add the shrink to your overall conduit length so the run lands at the target.
Assumptions
- 30° offset bender markings on both bends.
- Measurements are center-of-bend to center-of-bend.
- Shop rule-of-thumb shrink for 30°: 1/4 in. per inch of rise.
Basis
This is trade math, not an NEC rule. Check the marks on your own bender before you bend.
Questions electricians ask
What is the multiplier for a 30° offset?
2. One divided by sin(30°) is exactly 2, so the distance between bends is twice the offset depth.
What is the multiplier for a 15° offset?
About 3.9. One divided by sin(15°) is 3.864, so a 4 in. offset needs marks about 15-1/2 in. apart.
What is the multiplier for a 20° offset?
About 2.9. One divided by sin(20°) is 2.924.
What is the multiplier for a 22.5° offset?
About 2.6. One divided by sin(22.5°) is 2.613.
What is the multiplier for a 45° offset?
About 1.41. One divided by sin(45°) is 1.414, so a 4 in. offset needs marks about 5-5/8 in. apart. Shrink is about 3/8 in. per inch of offset.
What is the multiplier for a 10° offset?
About 5.76. One divided by sin(10°) is 5.759, so a 3 in. offset needs marks about 17-1/4 in. apart. Shrink is about 1/16 in. per inch of offset.
Does the offset multiplier change with conduit size?
No. The multiplier and the shrink per inch depend only on the bend angle, so the 45° number is the same for 1/2 in., 3/4 in., and 1 in. EMT. Trade size changes the bender you use, not the math.
What is shrink?
The conduit gets shorter in the direction of the run when you bend an offset, because part of its length now goes sideways. Add the shrink to your measurement so the offset lands where you want it.
How many degrees can I have between pull points?
No more than 360° total between pull points, the equivalent of four quarter bends. Each raceway article sets this limit, including the EMT rules in Article 358. A 30° offset uses 60° of it.
Practice it hands-on
Mark, bend, and strap 1/2 in. EMT with a hand bender, and keep every run at 360 degrees or less between pull points.
Teach it in one class
Free slides, quiz, and instructor note: Conduit bending (NEC 2026 Articles 344, 352, and 358).
How this calculator was built
The bending math is standard trigonometry, and it runs the same code as the Ask Shorty iPhone app. Automated tests check every calculator against hand-worked answers. Bender marks and take-up vary by manufacturer, so check yours.
How we test the calculators. See something wrong? Tell us and we will check it against the code.
Related calculators
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- 4-point saddleFour marks to cross a wide obstruction like a duct or beam.
- 90° stub-upWhere to mark the EMT for a stub at the height you need.
Have a code question the calculator doesn’t cover?
Ask Shorty in plain English. You get a straight answer with the NEC 2026 section it came from.