Conduit Offset Travel Calculator

A conduit offset requires two equal bends that move the raceway around an obstruction or onto a different plane while keeping the run parallel to its original path. The critical layout number is the travel between marks: the distance along the conduit between the first and second bend marks.

The Conduit Offset Travel Calculator determines that spacing from the required Offset rise and Bend angle. It then adds the travel to First mark from conduit end to establish the location of the second bend mark.

This is a conduit-bending layout calculation. It does not determine conductor ampacity, raceway fill, voltage drop, or branch-circuit and feeder requirements. Those electrical design decisions remain separate from the offset geometry.

Offset Travel Formula

For a standard two-bend offset using the same bend angle at each mark:

\(\displaystyle \text{Travel between marks} = \frac{\text{Offset rise}}{\sin(\text{Bend angle})}\)

The calculator also expresses the relationship as an Offset multiplier:

\(\displaystyle \text{Offset multiplier} = \frac{1}{\sin(\text{Bend angle})}\)

\(\displaystyle \text{Travel between marks} = \text{Offset rise} \times \text{Offset multiplier}\)

The second mark is then:

\(\displaystyle \text{Second bend mark} = \text{First bend mark} + \text{Travel between marks}\)

A 30-degree offset has a multiplier of 2. For every inch of perpendicular rise, the conduit needs 2 inches of travel between the bend marks.

Calculator Inputs

Input	Field Use
Offset rise	The required perpendicular movement of the conduit, measured as the offset depth or rise.
Bend angle	The angle used for each of the two offset bends. The calculator uses this angle to calculate travel and the offset multiplier.
First mark from conduit end	The distance from the selected conduit end or reference point to the first bend mark.

The bend angle must represent the actual bends planned for the offset. A larger angle shortens the travel distance but generally increases the amount of bend concentrated in a shorter section of raceway. A smaller angle creates a longer, more gradual offset.

Calculator Results

Result	Meaning
First bend mark	Repeats the entered reference distance for the first bend location.
Second bend mark	The layout location of the second bend mark, measured from the same conduit end or reference point.
Travel between marks	The center-to-center mark spacing required to produce the entered offset rise at the selected angle.
Offset multiplier	The multiplier produced by 1 / \sin(\text{Bend angle}).
Estimated shrink	The calculator’s estimated longitudinal shortening associated with the offset geometry.
Bend angle used	Confirms the angle used in the travel calculation.

The Estimated shrink result supports cut and placement planning. It should not be used as a substitute for verifying the finished conduit position against the actual installation reference points.

30-Degree Offset Example

Assume a conduit run must rise 4 inches. The first bend mark is located 24 inches from the conduit end, and both bends will be 30 degrees.

Field	Value
Offset rise	4 in
Bend angle	30 deg
First mark from conduit end	24 in

The travel calculation is:

\(\displaystyle \text{Travel} = \frac{4}{\sin(30^\circ)}\)

Because:

\(\displaystyle \sin(30^\circ) = 0.5\)

\(\displaystyle \text{Travel} = \frac{4}{0.5} = 8 \text{ in}\)

The offset multiplier is:

\(\displaystyle \frac{1}{0.5} = 2\)

The second bend mark is:

\(\displaystyle 24 \text{ in} + 8 \text{ in} = 32 \text{ in}\)

The resulting layout values are:

Result	Value
First bend mark	24 in
Second bend mark	32 in
Travel between marks	8 in
Offset multiplier	2 x
Estimated shrink	1.0718 in
Bend angle used	30 deg

Mark the conduit at 24 inches and 32 inches from the same reference end. The two bends must be oriented correctly so the conduit moves in the intended direction rather than forming a back-to-back error, dogleg, or reverse offset.

Field Layout Verification

Travel is a geometric result, but a successful conduit offset depends on the actual bender, conduit, and installed conditions. Verify the bend direction, mark interpretation, springback, conduit size, bender shoe and hook position, and remaining straight length before making the bends.

The calculator does not use a manufacturer-specific bender table. Bender markings and the point at which a particular tool starts or centers a bend can vary, so the calculated marks should be checked against the equipment and bending method being used.

Confirm that the finished offset clears the obstruction while preserving alignment with the downstream raceway. Where the conduit supports branch-circuit or feeder conductors, separately verify conductor pulling space, raceway fill, bend limitations, support locations, and any applicable AHJ or project requirements.