Conduit Bending Chart

This is the chart electricians tape inside their gang box lid: every multiplier and shrink factor for the bend angles you will actually use, on one page. Bookmark it.

Multiplier & shrink chart

Mark spacing = obstacle height × multiplier. Total shrink = height × shrink per inch.

Why the multiplier works

The multiplier is the cosecant of the bend angle — 1/sin θ. At 30°, sin 30° = 0.5, so the multiplier is exactly 2.0: a 6" obstacle needs 12" between marks, no calculator required. The numbers above are rounded to what fits on a tape measure; the calculator on this site uses the full-precision values.

How to pick the angle

• Default to 30°. The math is trivial (×2) and shrink stays moderate. Most journeymen bend 30° unless there is a reason not to.
• Go shallow (22.5°, 15°, 10°) when shrink is the enemy — long runs with multiple bends, or couplings that must land exactly.
• Go steep (45°, 60°) when you must clear a tall obstacle in a short horizontal distance. Accept the extra shrink and add it to your cut length.

Take-up reference (hand benders, EMT)

Take-up is a property of the bender head, not a formula — always confirm against the markings on the bender in your hands.

Chart vs. calculator

The chart gives you spacing and shrink in seconds. The calculator adds what the chart cannot: exact mark locations from your bender's actual radius, remaining straight lengths, minimum stick length, and a warning before a bend is physically impossible. Use the chart for quick layout, the calculator before you cut.