Conduit Bending Calculator

Calculate offset multipliers, shrink, 90° stub-up take-up, 3-point and 4-point saddles, rolling offsets, and 360° bend limits for EMT & RMC.

NEC edition

Inputs

in
in
in
deg

Check against 360° NEC §358.24 limit

VoltageLab app

Take this toolkit with you on the job

The full VoltageLab electrician app — wire tables, code lookups and job-site calculators offline, on Android and iOS.

Get it on Google Play Download on the App Store
⚡ Test your knowledge
NEC Article 220 was renumbered in the 2026 code cycle. What is the new article number?
  • A. Art. 100
  • B. Art. 120
  • C. Art. 200
  • D. Art. 230
💡 NEC 2026 renumbered Article 220 (Branch-Circuit, Feeder, and Service Calculations) to Article 120.
Energy Management Systems were moved from Article 750 to which article in NEC 2026?
  • A. Art. 100
  • B. Art. 125
  • C. Art. 130
  • D. Art. 150
💡 NEC 2026 moved Energy Management Systems from Article 750 to Article 130.
Which NEC standard size overcurrent device comes after 90A?
  • A. 95A
  • B. 100A
  • C. 110A
  • D. 105A
💡 Per NEC §240.6(A), the standard sizes are …90, 100, 110, 125… There is no 95A standard size.

VoltageLab app

Studying for your electrical exam?

Practice NEC exam questions with full explanations and progress tracking, right on your phone.

Get it on Google Play Download on the App Store

How it works & the NEC rules behind it

Conduit bending requires precise geometry to clear obstacles while keeping the run parallel and within NEC code limits. Under NEC §358.24 (EMT) and §344.24 (RMC), the total number of bends between pull points (boxes, conduit bodies, or panels) must not exceed 360 degrees (four quarter bends).

Common Bending Formulas & Multipliers:

  • Offset Bends: Distance between marks = Offset Depth × Angle Multiplier. Shrink = Offset Depth × Shrink Constant.
  • 90° Stub-Up: Mark 1 = Desired Stub Height − Deduct (Take-Up).
  • 3-Point Saddle: Used to bridge a single pipe/conduit. Center mark = Distance to obstruction + Shrink. Outer marks = Obstruction Height × Saddle Multiplier from center mark.
  • 4-Point Saddle: Composed of two standard offsets placed back-to-back around a wide obstacle.
  • Rolling Offset: A compound offset shifting both vertically (rise) and horizontally (roll). True Offset = √(Rise² + Roll²).

Formulas & equations

Offset Distance Between Marks = Offset Depth × Multiplier (cosec θ) Total Shrink = Offset Depth × Shrink per Inch 90° Stub Mark = Desired Stub Length − Bender Take-Up (Deduct) Rolling Offset True Depth = √(Rise² + Roll²) Max Allowable Total Bends Between Pull Points ≤ 360° (§358.24)

NEC reference table

Bend Angle (θ) Multiplier (Distance) Shrink per Inch of Offset 3-Point Saddle (Center / Sides)
10°6.01/16" (0.0625")—
22.5°2.63/16" (0.1875")45° Center / 22.5° Outer (2.5×)
30°2.01/4" (0.2500")60° Center / 30° Outer (2.0×)
45°1.4143/8" (0.3750")90° Center / 45° Outer (1.4×)
60°1.1551/2" (0.5000")—

*Standard Hand Bender Deduct Values (EMT): 1/2" = 5", 3/4" = 6", 1" = 8", 1-1/4" = 11".

Worked example, step by step

Example Calculation: 6" Offset Using 30° Bends in 3/4" EMT

Goal: Step over a 6-inch obstruction in a 3/4" EMT run.

  • Step 1 (Find Multiplier): A 30° bend has a distance multiplier of 2.0.
  • Step 2 (Distance Between Marks): 6" depth × 2.0 = 12.0 inches between Mark 1 and Mark 2.
  • Step 3 (Calculate Shrink): Shrink constant for 30° is 1/4" per inch of offset. Total shrink = 6 × 0.25" = 1.5 inches.
  • Step 4 (Total Degrees): Two 30° bends = 60° total toward the 360° maximum limit per §358.24.

Frequently asked questions

Under NEC §358.24 (for EMT) and §344.24 (for RMC), there shall not be more than the equivalent of four quarter bends (360 degrees total) between pull points such as conduit bodies, junction boxes, or panels.

Conduit shrink is the apparent shortening of the overall run when conduit travels over an obstruction on an angle (hypotenuse) rather than in a straight line. To land your box exactly at the required point, your first mark must be positioned ahead by the total shrink amount.

The offset multiplier converts the height of an obstruction into the distance between your two bend marks. Multiply the offset depth by the multiplier for your chosen bend angle (e.g. 2.0 for 30°, 1.414 for 45°) to get the mark-to-mark distance along the conduit.

Related NEC calculators

Other tools in the same install chain:

NEC sizing

Conduit Fill Calculator

Calculate raceway fill percentage and minimum conduit size per NEC Chapter 9 Tables 1, 4, and 5. Supports EMT, IMC, RMC, PVC-40, PVC-80, ENT, FMC, and LFMC with mixed wire sizes.

Open NEC sizing

Pull & Junction Box Sizing Calculator

Determine minimum pull and junction box dimensions for conductors #4 AWG and larger per NEC §314.28. Covers 8× straight pulls, 6× angle pulls, and U-pulls.

Open NEC sizing

Box Fill Calculator

Calculate electrical junction box and device box fill volume in cubic inches per NEC §314.16. Covers conductors, devices, internal clamps, studs, and grounding wires.

Open NEC sizing

Wire Pulling Tension Calculator

Calculate conduit wire pulling tension, bend multiplier, Sidewall Bearing Pressure (SWBP), and pulling grip limits per IEEE 576 & NEC Ch. 9.

Open