By Blissom · Updated 2026-10-23
The terms, doing the workConduit Bending Calculator for Android · $7.99 one time · offline · no ads
Get the appMeasurements and numbers
- Take-up (deduct)
- The amount subtracted from a stub height to find where the bender arrow goes for a 90°. It is usually marked on the shoe; Klein's guides give 5" for 1/2" EMT, 6" for 3/4", 8" for 1" and 11" for 1-1/4", and other makers can differ. Full stub tables per size are on the 1/2", 3/4", 1" and 1-1/4" EMT charts. 3/4" EMT Chart →
- Gain
- The conduit a bend saves compared with two straight legs meeting at a sharp corner. For a 90° on centerline radius R it is 2R − πR/2, about 0.43 × R; measured to the back of the 90, add one conduit diameter. Used when cutting a piece with 90s to length. Bender Take-Up Chart →
- Shrink
- How much shorter a run becomes because of an offset or saddle, since part of the conduit travels diagonally. At 30° the field rule is about 1/4" per inch of offset depth; the ideal sharp-corner value is depth × tan(θ ÷ 2). It moves the marks when an offset must be complete by a fixed point. Offset →
- Multiplier
- The number that turns offset depth into the distance between bends: 10° = 6, 22.5° = 2.6, 30° = 2, 45° = 1.4, 60° = 1.2. It is the cosecant (1 ÷ sine) of the bend angle. Bending Multiplier Chart →
- Depth (offset depth)
- How far an offset or saddle moves the conduit, measured square to the run.
- Rise
- The height a kick or stub must reach, measured square to the surface the conduit runs on. Kick →
- Travel
- The length of conduit between bend centers, or from a bend to where the rise is reached, measured along the pipe.
- Run
- The horizontal distance a bend covers, measured along the floor or wall rather than along the pipe.
- Developed length
- The length of conduit inside a bend (the arc). For a 90° on radius R it is π × R ÷ 2. Concentric Bend Chart →
- Centerline radius
- The radius of a bend measured to the middle of the conduit. NEC Chapter 9, Table 2 sets the minimum for one-shot and full-shoe bends: 4" for 1/2" EMT, 4-1/2" for 3/4", 5-3/4" for 1". Real shoes match or exceed it; a Klein 51606 1/2" shoe is 4-5/8".
- True offset
- The actual depth of a rolling offset: √(horizontal² + vertical²). Rolling Offset →
Marks on the bender
- Arrow
- The main reference mark on a hand bender, used for stubs, offsets and kicks. For a stub-up the arrow goes on the mark with the hook facing the end.
- Star point
- On benders that have one, a mark cast into the shoe that shows the back of a 90° when the bender is reversed. Used for back-to-back 90s without subtracting the take-up. Back-to-Back 90s →
- Rim notch (teardrop)
- On most benders, the mark for the center of a bend, used for the center bend of a 3-point saddle. 3-Point Saddle →
- Degree marks
- Sight lines on the shoe at 10°, 22.5°, 30°, 45° and 60°. The bend has reached the angle when the conduit lines up with the mark.
- Hook
- The end of the shoe that grips the conduit. Its direction relative to the mark decides where the bend lands.
Bends
- Stub-up (90° stub)
- A 90° bend that turns the conduit up out of a floor or wall to a target height. 90° Stub-Up →
- Offset
- Two equal bends in opposite directions that move the run over an obstruction or off a surface and bring it back parallel. Offset →
- Box offset
- A shallow offset, about 1/2", that lets conduit enter a box or fitting flush with the surface. Usually two 10° bends, marks about 3" apart.
- Kick
- A single bend that angles the conduit away from a surface. Kick →
- Kicked 90
- A 90° stub with a kick in its horizontal leg, bent in a plane at right angles to the 90, so the run angles off the wall while the stub stays plumb.
- 3-point saddle
- Three bends (a center bend and two at half its angle) that lift the conduit over a narrow obstruction such as a pipe. 3-Point Saddle →
- 4-point saddle
- Two offsets, one up and one back down, with a raised level section, used to clear a wide obstruction such as a duct. 4-Point Saddle →
- Back-to-back 90s
- Two 90s in one piece making a U, with a target distance between the outsides (backs) of the two bends. Back-to-Back 90s →
- Rolling offset
- An offset that moves the run over and up at the same time, bent in a plane rolled between horizontal and vertical. Rolling Offset →
- Parallel offsets
- The same offset bent in several conduits on a rack, with each conduit's marks moved spacing × tan(θ ÷ 2) so the runs stay evenly spaced.
- Segmented bend (shots)
- A large-radius bend made from several small bends called shots. Segmented 90 →
- Concentric bends
- Nested 90s on a rack, each conduit on a radius larger than the one inside it by the center-to-center spacing. Concentric Bend Chart →
Problems and technique
- Dog-leg
- A bend set that ends up twisted out of its intended plane, so the conduit kicks sideways: an offset whose two bends are not in one plane (the conduit was not turned exactly 180° between them), or a kicked 90 rolled by the wrong amount between the 90 and the kick.
- Spring-back
- The amount a bend relaxes when bending pressure is released. It varies with conduit size, material, bender and bend angle, so follow the bender maker’s guidance, check the angle after release and adjust.
- Kink
- A flattened or buckled bend. Kinked conduit effectively reduces the internal diameter, which the NEC does not allow (for EMT, 358.24(A)), and must be cut out.
- Hickey
- A tool for bending rigid conduit in place, and also a fitting used to hang fixtures.
Code and conduit
- 360° rule
- The NEC limit of 360° of bends in total between pull points (for EMT, 358.24(B) in the 2023 NEC; 358.26 before). 360° Bend Counter →
- Conduit fill
- The share of a raceway's internal area the conductors take up. NEC Chapter 9 allows 53% for one conductor, 31% for two and 40% for three or more. Conduit Fill →
- Nipple
- A short section of conduit or tubing between boxes, cabinets or similar enclosures. Under NEC Chapter 9, Note 4, a nipple no longer than 24" may be filled to 60% of its internal area; longer nipples follow the normal fill limits.
- Box fill
- The volume a box needs for its conductors, devices, clamps and grounds, per NEC 314.16. Box Fill →
- EMT
- Electrical metallic tubing: a thin-wall, unthreaded metal raceway, most often galvanized steel but also made in stainless steel and aluminum, joined with listed set-screw or compression fittings and bent with hand benders.
- RMC and IMC
- Rigid metal conduit and intermediate metal conduit: threadable metal raceways with thicker walls than EMT. RMC is made in steel, stainless steel, aluminum and red brass; IMC in steel and stainless steel. On hand benders, the next EMT size up bends it when the shoe is rated for it (a 3/4" EMT shoe bends 1/2" rigid).
- PVC
- Rigid PVC conduit, Schedule 40 or 80. It is usually bent with heat (a hot box or heat blanket), not with an EMT hand bender.
Sources: NEC 2023 358.24 and Chapter 9, Table 2; Klein Tools Conduit Bender Guide (stub take-up, offset multipliers and shrink, saddles). Method.
The terms, doing the work
- Take-up, gain and radius for your exact shoe
- Shrink and multipliers applied for you, at any angle
- Guide mode explains each step as you bend
- Offline, in five languages
Android only. There is no iPhone version yet; the free calculators on this site work on any phone.
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