Conduit offset worksheet

Offset Bend Multiplier Calculator

Find the offset bend multiplier for a selected bend angle and use it to calculate spacing between the two bend marks.

Calculate Offset Bend Multiplier

Enter offset height and bend angle to calculate the multiplier and distance between marks for a simple two-bend offset.

Result

Multiplier

2.00

Bend spacing

12 in

Distance between the two bend marks for a simple offset.

Result notes

Keep the entered values, assumptions, and result together when adding this calculation to job notes or submittal records. Final installation choices should align with the applicable code edition, equipment listing, manufacturer instructions, local amendments, and AHJ requirements.

Formula and field context

Find the offset bend multiplier for a selected bend angle and use it to calculate spacing between the two bend marks.

Formula context

Offset Bend Multiplier Chart

For a two-bend conduit offset, distance between bends equals offset height times the selected multiplier: 10 deg = 6.0, 22.5 deg = 2.6, 30 deg = 2.0, 45 deg = 1.414, and 60 deg = 1.155. A 4 inch offset at 30 deg uses the 2.0 multiplier, so the marks are 8 inches apart before shrink and bender-reference checks. Use this chart for common offset multiplier questions without creating angle-specific pages.

Formula

Distance between bends = offset height x multiplier. Shrink allowance = offset height x shrink per inch.

Variables to keep with the result

  • Offset height is the rise or drop needed to clear an obstruction or change elevation.
  • Bend angle is the equal angle used for both bends in the offset.
  • Multiplier converts offset height into mark spacing along the conduit.
  • Shrink allowance estimates how much the finished run shortens through the offset geometry.

Formula and variables

For a simple two-bend conduit offset, the bend multiplier is multiplier = 1 / sin(angle). The spacing between the two bend marks is spacing = offset height x multiplier. Offset height is the perpendicular rise needed to clear the obstruction or change elevation. Bend angle is the angle used for each of the two matching bends. The multiplier converts the true offset height into the straight-line distance measured along the conduit between marks.

Field example

A 6 in offset using 30 degree bends has a multiplier of 1 / sin(30 degrees), which equals 2.0. The mark spacing is 6 in x 2.0 = 12 in. If the same 6 in offset is bent with 22.5 degree bends, the multiplier is about 2.613, so the marks are about 15.68 in apart. Smaller bend angles make the offset longer and easier to pull through, while steeper bend angles make the offset more compact.

Assumptions and layout limits

This worksheet covers a standard two-bend offset where both bends use the same angle and stay in the same plane. It does not account for bender take-up, conduit size, bending radius, couplings, box offsets, rolling offsets, saddle bends, or obstacles that require more than one offset. Use consistent reference points on the conduit and confirm that the bender arrow, star, or rim mark matches the layout method being used.

Common mistakes

Common mistakes include using the shrink factor as the multiplier, measuring the obstruction distance instead of the distance between bend marks, mixing degree values with multiplier values, and rotating the second bend out of plane. Keep the selected angle, offset height, calculated spacing, and field reference mark together on the layout note before bending.

Common Questions

What multiplier should I use for a 30 degree offset?
The 30 degree offset multiplier is 2.0, so the distance between bend marks is twice the offset height.
Is offset multiplier the same as shrink?
No. The multiplier sets the distance between the two bend marks. Shrink is the amount the finished offset shortens the overall conduit run.
When should I use the full offset bend calculator?
Use the full offset bend calculator when you need a complete layout that includes obstruction distance, first mark, second mark, and shrink together.