What is the multiplier for a 30 degree bend?

The multiplier for a 30-degree bend is 2.0. This means for every inch of offset rise, the distance between bends is 2 inches.

How do I calculate shrink?

Shrink is the difference between the hypotenuse (travel) and the run. For a 30-degree bend, shrink is approximately 1/4 inch per inch of offset rise.

Take-up is the amount of conduit length 'used' by the bender to form a 90-degree bend. You must subtract the take-up from your desired stub height to find the start mark.

Conduit Bending Planner

Lay out offsets, 3‑bend saddles, 4‑bend saddles, 90° stubs, and back‑to‑back 90s. Get mark spacing, shrink, and take‑up, with a live visual and a phone tilt readout for angle checks.

All math runs locally in your browser. No uploads. No tracking.

Mode & basics

Mode Units Decimal places

Geometry

Angle (°) (outer bends) Offset height / rise Obstacle/plateau width (saddles)

First mark from end Take-up per 90° (stub/b2b) Enter your bender's actual deduct. Springback (° to add)

Angle presets, multipliers & shrink (info)

Offset multiplier M = 1 / tan(θ). Common M values: 10° 5.76, 15° 3.86, 22.5° 2.61, 30° 2.00, 45° 1.41, 60° 1.15.

Approx. shrink per inch of rise for a two-bend offset (rules of thumb): 10° ≈ 1⁄16 in, 15° ≈ 1⁄8 in, 22.5° ≈ 3⁄16 in, 30° ≈ 1⁄4 in, 45° ≈ 3⁄8 in, 60° ≈ 1⁄2 in.

Results

Enter your details and select Calculate.

Visual layout

Drag the blue marks along the conduit line to experiment; values update on Calculate.

Phone tilt (optional)

Use your phone to check bend angle. Grant motion permission if prompted.

0.0°

Method & assumptions

Offset (two-bend): spacing S = M × rise, where M = 1 / tan(θ). Shrink ≈ rise × shrinkFactor(θ). We subtract shrink from the advance.
Three-bend saddle: outer bends at θ, center bend at 2θ. Place marks: first outer; then S = M × rise to center; then S again to second outer.
Four-bend saddle: four bends all at θ. Spacing pattern along the conduit: S, then obstacle width, then S. Here S = M × rise.
90° stub: stub length to back-of-bend = desired stub + take-up; springback adds to the dial setting.
Back-to-back 90s: inside length between 90s = desired inside dimension − 2 × take-up.

About this free conduit bending calculator

This online conduit bending calculator plans two-bend offsets, three-bend saddles, four-bend saddles, 90° stubs, and back-to-back 90s. It shows mark spacing, estimated shrink, and lets you enter your own take-up and springback. Everything runs in your browser, with a visual layout, shareable URL, and PNG/SVG export.

Demystifying the "Pipefitter's Triangle"

Every offset forms a right-angle triangle. Understanding this geometry helps you visualize the bend:

Rise (Offset): The vertical distance the pipe must move to clear the obstacle.
Spread (Run): The horizontal distance the pipe covers during the offset.
Travel: The diagonal length of the pipe between bends (the hypotenuse).

The math relies on the Pythagorean theorem: $\text{Travel} = \sqrt{\text{Rise}^2 + \text{Spread}^2}$.

The Multiplier Method

Field electricians use Multipliers to avoid complex trigonometry on the ladder. To find the distance between bends (Travel), simply measure your desired Offset and multiply it by the Multiplier for your chosen angle.

Bend Angle	Multiplier	Shrink Constant (per inch of offset)
10°	6.0	1/16"
22.5°	2.6	3/16" (0.19)
30°	2.0	1/4" (0.27)
45°	1.414	3/8" (0.41)
60°	1.15	1/2" (0.50)

Example: A 5-inch offset with 30° bends requires a distance of $5 \times 2 = 10$ inches between marks.

Defining Shrink, Gain, and Take-Up

Confusion regarding these terms is a common source of error. Here is what they mean:

Shrink: The reduction in total linear length caused by the pipe following the diagonal path rather than the straight line. You must add the total shrink to your measurement before cutting, or your run will be short.
Gain: The length of pipe saved by bending in an arc rather than a sharp 90° corner. This is critical for determining total length.
Take-Up: The amount of pipe the bender "uses" to form the bend. This is specific to the bender shoe size (e.g., 5" take-up for 1/2" EMT). Subtract the take-up from your desired stub height to find your start mark.

Conduit bending FAQ

Do I enter the bend angle on the bender or the final angle?

Enter the intended finished angle. The tool adds your springback value to the dial target so you can slightly over-bend and return to the intended angle.

Does take-up vary by bender and conduit size?

Yes. Enter your own take-up (deduct) measured from your bender and size. The tool uses your value for 90° stubs and back-to-back 90s.

How accurate are shrink factors?

They are common field approximations. For critical work, measure on your specific bender and material and adjust the shrink factor accordingly.