Rolling Offset Calculator
Reference helper for common field math. Use at your own risk; verify against your method, tooling, and applicable code/manufacturer data.
Print creates a simple job ticket with inputs and results. This tool runs 100% in your browser.
Rolling Offset Math & Formulas
A rolling offset is essentially a 3D triangle problem. When a pipe needs to change elevation (Rise) and horizontal position (Offset) at the same time, it creates a "Resultant" offset that is larger than either individual measurement.
Step 1: Find the Resultant
The first step is to calculate the true offset distance using the Pythagorean theorem:
$$Resultant = \sqrt{Rise^2 + Offset^2}$$
Step 2: Calculate Travel
Once you have the Resultant, you treat it like a standard single-plane offset. To find the distance between bends (Travel), multiply the Resultant by the cosecant of the bend angle (or divide by the sine):
$$Travel = \frac{Resultant}{\sin(\theta)}$$
Step 3: Calculate Advance
The "Advance" is how far the pipe moves along its original path while making the offset. This is found by dividing the Resultant by the tangent of the bend angle:
$$Advance = \frac{Resultant}{\tan(\theta)}$$
Rolling Offset FAQ
What is a rolling offset?
A rolling offset is a conduit bend that changes direction in both the vertical and horizontal planes simultaneously, effectively 'rolling' the pipe to a new position.
How do I find the angle of a rolling offset?
You typically choose a standard bend angle (like 30° or 45°) based on the space available and ease of pulling wire. The calculator then determines the travel distance required for that angle.
Does this calculator account for shrink?
This calculator provides the center-to-center travel distance. You should apply shrink calculations based on your specific bender and the resultant offset to ensure the total length is correct.