A rolling offset (also called a combination offset) occurs when a conduit must change direction in both the vertical and horizontal planes simultaneously. This is common when routing conduit around structural beams, transitioning from one elevation to another while also moving laterally. The rolling offset calculation uses the Pythagorean theorem on the two offset components — vertical rise and horizontal offset — to find the true diagonal offset distance. The true offset distance is then used to compute the travel between bends and the bend angles just as you would for a simple offset. SparkShift's conduit bending calculator visualizes the rolling offset in 3D so you can confirm the geometry before bending.
Rise = 4", Run = 3": True diagonal offset = √(4² + 3²) = √(16 + 9) = √25 = 5". Travel for 30° offset = 5 / sin(30°) = 10". Roll angle = arctan(3/4) ≈ 36.9°. Rotate the conduit 36.9° from horizontal before making the two 30° bends.
This is a variant of the full Conduit Bending Calculator — which supports all bend types with live 3D visualization and supports EMT, rigid, and PVC conduit sizes.
Try all options in the full Conduit Bending Calculator →