Concentric bends are used when multiple parallel conduits must all make the same turn — for example, a bank of five 1" conduits turning together around a corner. Because each successive conduit is farther from the center of the turn radius, it must travel a longer arc. The extra distance added for each conduit is calculated as: additional travel = 2π × center-to-center spacing × (bend angle / 360°). For a 90° turn with conduits spaced 1.5" center-to-center, each successive conduit needs approximately 2.36" more travel. This calculator provides the mark location adjustments for each conduit in a bank so that all conduits emerge parallel and evenly spaced.
Four 3/4" conduits at 1.5" spacing, 90° bend: Extra travel per conduit = 2π × 1.5 × 90/360 = 2.36". Conduit 1: base travel (reference). Conduit 2: add 2.36". Conduit 3: add 4.71". Conduit 4: add 7.07". Mark each conduit accordingly so all emerge parallel.
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 →