Free Conduit Bending Tool

Offset Bend Calculator

Enter your obstruction height and bend angle to get exact bend marks, travel distance, and shrink — computed with precise trigonometry, not rounded shop-table guesses.

Obstruction height (H) inch, decimals allowed (e.g. 7.5)

Bend angle

Distance to first bend inch, optional

First mark

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Second mark

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Mark spacing (travel)

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Shrink — add to cut length

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How an offset bend works

An offset uses two equal-angle bends to shift a run of conduit sideways — around a beam, duct, or another obstruction — while keeping it parallel to its original line on the other side. The mark spacing is the straight-line distance between the two bend marks, measured along the conduit. The shrink is the amount the offset shortens the conduit's overall run compared to a straight piece — you add this back to your cut length so the far end still lands where it needs to.

This calculator uses exact trigonometry (travel = H ÷ sin(θ), shrink = H × tan(θ/2)) rather than the rounded shop multiplier tables (like "30° = 2×") that are handy to memorize but drift from the true value — especially for shrink, where the classic tables round to the nearest 1/16" per inch of height.

Frequently asked questions

Why does my answer differ from the classic multiplier chart?

Classic charts (2.0× for 30°, 1.4× for 45°, etc.) are rounded field shortcuts. This calculator uses exact trigonometry, so results can differ by a small fraction — usually under 1/16" for typical heights. Both are valid; exact math just removes the rounding error before you cut.

What angle should I use for an offset?

30° and 45° are the most common. Shallower angles (10°, 22.5°) need a longer run of conduit but are easier to fish through tight spaces; steeper angles (45°, 60°) get you around the obstruction faster but require more clearance to bend.

Does this work for EMT, IMC, and rigid conduit?

Yes — the offset geometry is identical regardless of conduit material. What differs between materials is how much force the bend takes and the bender you use, not the marks themselves.