Offset Bend Calculator

An offset moves conduit around an obstacle — or up to box height — using two equal bends in opposite directions. The math is simple once you know the multiplier: mark spacing equals offset height times the multiplier for your bend angle.

Multiplier and shrink chart

The multiplier is the cosecant of the bend angle (1/sin θ). Shrink is given per inch of offset height — multiply by your height to get total shrink.

30° is the everyday choice — the math is trivial (×2), and shrink stays moderate. Use 22.5° or 10° in tight quarters where every fraction of shrink matters; use 45° or 60° when you need to clear a tall obstacle in a short distance.

Worked example

You need a 6" offset at 30°. Mark spacing = 6 × 2.0 = 12". Shrink = 6 × 1/4" = 1.5" — the finished run comes up 1.5" short, so add that to your total conduit length before cutting.

How to bend an offset, step by step

1. Mark the location of the first bend on the conduit.
2. Measure the spacing from the chart and mark the second bend.
3. Put the bender's arrow on the first mark and bend to your angle (30°).
4. Flip the bender 180° so the handle points the opposite way, line the arrow up with the second mark, and bend back to 30°.
5. Sight down the conduit: both ends parallel, offset height correct.

Mistakes to avoid

• Forgetting shrink — the single most common offset error. The calculator adds it for you.
• Bending both bends the same direction, which makes a useless zigzag instead of an offset.
• Using the multiplier for 30° but actually bending 45° — check the angle against the bender's degree marks, not by feel.