RACEWAY · CALCULATOR

Conduit bending calculator

Free conduit bending calculator: get bend spacing and offset shrink from offset rise, rolling offset, bend angle, stub height and bender take-up.

Written by Chameera Sampath · Not yet reviewed by a licensed electrician. See the methodology.

US (NEC) only · NFPA 70 / NEC — locally adopted editionDefaults are US values. Verify the locally adopted NEC edition and project data.Official reference ↗

Project inputs

Measurements

Bend layoutOffset rise

Rolling offset

Bend angle

Updates as inputs change. Unit changes preserve the same physical values.

THE MATH BEHIND THE ANSWER

Method & assumptions

Offset: L = H/sin θ, shrink = H tan(θ/2). Saddle: outer angle = center angle/2. Stub: mark = height − take-up.

Ideal straight-segment offset / three-bend saddle geometry. Bend radius and bender marks require manufacturer corrections; take-up is bender-specific. Four-bend saddles can be formed as two verified offsets.

Results do not check every aspect of an electrical installation. The calculators follow US (NEC) practice only; a regional preset changes defaults such as voltage and units, and no result certifies NEC compliance.

Sources and validation →

Worked example

Bend layout: Two-bend / rolling offset · Offset rise: 6 in · Rolling offset: 0 in · Bend angle: 30 °

Bend spacing: 12 in · Offset shrink: 1.608 in

This example uses the stated inputs; results for the entered values appear above.

Explore the raceway branch →See the related electrical concepts →

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