Conduit bending is one of the core skills that separates a competent electrician from a beginner. Anyone can make a 90-degree bend. The bender does most of the work. The real skill is in offsets, saddles, kicks, and compound bends that route conduit neatly through congested spaces. Getting the math right (multipliers and shrink allowances) means the conduit lands where it needs to without being cut short, running long, or looking like it was installed by someone who does not care about the craft.
This guide covers the essential bending calculations for EMT and rigid conduit, the multipliers and shrink values you need to know for offset and saddle bends, practical layout techniques for marking and bending, and common mistakes that waste conduit and time.
Offset Bends: The Foundation of Conduit Routing
An offset bend moves the conduit from one plane to another, typically to go around an obstruction or transition from surface-mounted to a different mounting plane. An offset uses two equal bends in opposite directions, connected by a straight section (the travel). The most common offset angles are 10, 22.5, 30, and 45 degrees.
The two numbers you need for every offset are the multiplier (to calculate the distance between bend marks) and the shrink (to account for the conduit getting "shorter" as it offsets). The multiplier is applied to the offset depth: Mark Spacing = Offset Depth × Multiplier. The shrink is subtracted from the overall length to compensate for the path change.
Multipliers by angle: 10° = 6.0, 22.5° = 2.6, 30° = 2.0, 45° = 1.414, 60° = 1.155. These are the cosecant of the bend angle. The 30-degree offset is the most commonly used because the multiplier of 2.0 is easy to calculate in your head. The mark spacing is simply twice the offset depth.
Shrink by angle: 10° = 1/16" per inch of offset, 22.5° = 3/16" per inch, 30° = 1/4" per inch, 45° = 3/8" per inch, 60° = 1/2" per inch. For a 6-inch offset at 30 degrees: shrink = 6 × 1/4 = 1.5 inches. Start your first mark 1.5 inches closer to the end of the conduit to compensate.
Mark Spacing = Offset Depth × Multiplier
Shrink = Offset Depth × Shrink Constant
By angle:
10°: Multiplier = 6.0, Shrink = 1/16"/inch
22.5°: Multiplier = 2.6, Shrink = 3/16"/inch
30°: Multiplier = 2.0, Shrink = 1/4"/inch
45°: Multiplier = 1.414, Shrink = 3/8"/inch
60°: Multiplier = 1.155, Shrink = 1/2"/inch
Conduit Bending Calculator
Conduit bending calculator for EMT and rigid conduit. Benfield method for offsets, saddles, stub-ups, and back-to-back 90s. Shrink, multipliers, and marks.
Saddle Bends: Going Over Obstructions
A saddle bend routes the conduit over an obstruction and back to the original plane. A 3-point saddle uses three bends: a center bend (typically 45 degrees) flanked by two half-angle bends (22.5 degrees each) on either side. The conduit rises over the obstruction and returns to its original elevation.
For a 3-point saddle with a 45-degree center bend: mark the center of the obstruction on the conduit. Then mark 2.5 times the saddle depth on each side of the center mark (for 45° center / 22.5° outer bends). The center bend is made at the center mark, and the two outer bends are made at the side marks, in the opposite direction from the center bend. Shrink for a 3-point saddle at 45°/22.5°: approximately 3/16 inch per inch of saddle depth.
A 4-point saddle is essentially two offset bends in series, an offset up and then an offset back down. Use the same multiplier and shrink calculations as for offsets, applied twice. The 4-point saddle is easier to calculate and bend consistently, but it takes more conduit length than a 3-point saddle for the same obstruction height.
For small obstructions (under 2 inches), a 3-point saddle with a 22.5-degree center bend and 11.25-degree outer bends produces a gentle, barely noticeable deviation that looks professional. For larger obstructions (3+ inches), the 45/22.5 combination is the standard. Match the saddle angles to the obstruction height and the aesthetic expectations of the installation.
1. Mark center of obstruction on conduit
2. Mark 2.5 × saddle depth on each side of center
3. Bend center mark at 45° (toward obstruction)
4. Bend each side mark at 22.5° (away from obstruction)
5. Apply shrink: 3/16" per inch of saddle depth
Verify the conduit clears the obstruction by at least 1/4" before securing.
Conduit Bending Calculator
Conduit bending calculator for EMT and rigid conduit. Benfield method for offsets, saddles, stub-ups, and back-to-back 90s. Shrink, multipliers, and marks.
EMT vs Rigid: Bending Differences
EMT (Electrical Metallic Tubing): Thin-walled steel tubing that bends easily with a hand bender. EMT is the most commonly bent conduit type and is used for most commercial and light industrial exposed and concealed wiring. Hand benders for EMT come in 1/2", 3/4", 1", and 1-1/4" sizes. Larger sizes require mechanical or hydraulic benders.
Rigid metal conduit (RMC) and IMC (Intermediate Metal Conduit): Thick-walled steel conduit that requires significantly more force to bend. Rigid conduit above 1 inch is typically bent with a hydraulic bender or a Chicago-type bender. The bending radii are larger than EMT for the same trade size, which means the stub-up dimensions and gain calculations differ. Always use the shoe dimensions from the specific bender being used, not generic values.
PVC conduit: Bent by heating with a heat blanket or hot box, then forming around a mandrel or by hand. PVC bending is a different process entirely. No mechanical bender is used. The conduit must be heated uniformly to approximately 275-300°F over the bend area, formed quickly before it cools, and held in position until it sets. PVC bending requires practice and patience; overheating causes the conduit to collapse or blister.
Aluminum conduit: Bends similarly to EMT but is softer and more prone to kinking and flattening. Use a bender with a smooth shoe and apply pressure gradually. Aluminum conduit cannot tolerate the aggressive bending techniques that work with steel EMT. Support the conduit behind the shoe during the bend to prevent kinking on the outside radius.
The minimum bend radius for conduit must not damage the conduit or make wire pulling difficult. Standard bender shoes are designed to meet these minimums. Do NOT bend conduit by hand without a bender (except PVC with heat). The resulting kinks restrict the internal area and make wire pulling nearly impossible. A kinked conduit must be cut out and replaced.
Practical Layout and Bending Techniques
Stub-up (90-degree bend): The most basic bend. Mark the conduit at the desired stub-up height minus the take-up of the bender (typically 5" for 1/2" EMT, 6" for 3/4", 8" for 1"). Place the mark at the arrow on the bender shoe, step on the foot piece, and pull the handle until the conduit is at 90 degrees. Check with a level or speed square. The take-up value is specific to each bender brand and size. Verify with your specific bender before marking production bends.
Back-to-back 90s: Two 90-degree bends creating a U-shape. Make the first bend as a stub-up. Measure the desired distance between the two legs along the back of the conduit (outside of the bends). Mark this distance from the back of the first bend. Place the mark at the front edge of the bender shoe and bend the second 90 in the opposite direction. The key measurement is the back-to-back distance, which is the outside measurement between the two straight sections.
Kick bend (less than 90 degrees): A partial bend used to angle conduit away from a wall or into a junction box. No specific take-up value applies. The bend develops at the shoe and you stop at the desired angle. Use a protractor or digital angle finder to verify the angle. For kicks into boxes, the angle is typically 10 to 30 degrees and the exact value is determined by the box location relative to the conduit run.
Parallel runs: When running multiple conduits in parallel (a conduit rack), each successive conduit must be bent at a slightly different distance from the end to account for the increasing centerline radius of each outer conduit. The spacing adjustment between parallel bends is typically the conduit spacing (usually 2 inches center-to-center for 1/2" EMT) divided by the tangent of the bend angle. For 30-degree offsets with 2" spacing: adjustment = 2 / tan(30°) = 3.46 inches between marks on successive conduits.
1/2" EMT: 5" take-up, 3/8" gain
3/4" EMT: 6" take-up, 1/2" gain
1" EMT: 8" take-up, 3/4" gain
1-1/4" EMT: 11" take-up, 1" gain
These vary by bender manufacturer. Always verify with your specific bender by making a test bend and measuring the actual stub height versus the mark location.
Conduit Bending Calculator
Conduit bending calculator for EMT and rigid conduit. Benfield method for offsets, saddles, stub-ups, and back-to-back 90s. Shrink, multipliers, and marks.
Common Bending Mistakes and How to Avoid Them
Forgetting shrink on offsets: This is the single most common bending error. If you do not account for shrink, the conduit ends up short of the target by the shrink amount. On a 6-inch offset at 30 degrees, the shrink is 1.5 inches, enough to miss a box knockout by more than an inch. Always calculate and apply shrink before making the first mark.
Inconsistent bend angles in an offset: Both bends in an offset must be exactly the same angle. If the first bend is 30 degrees and the second is 28 degrees, the conduit does not return to parallel. It angles off and the error compounds over the remaining run. Use the degree markings on the bender and check both bends with a protractor or level before moving on.
Overbending and trying to bend back: Bending conduit past the desired angle and then bending it back (spring-back correction) works for small adjustments (1-2 degrees) but creates a visible deformation if overdone. The area that was bent back shows as a flat spot or a slight S-curve. If you overbend significantly, cut the conduit and start over. It is faster and looks better than trying to fix a bad bend.
Not accounting for the 360-degree rule: NEC 344.26, 358.26, and equivalent articles limit the total bending between pull points to 360 degrees (the equivalent of four 90-degree bends). This includes all offsets, kicks, and saddles, not just 90-degree bends. A run with two 90s and two 30-degree offsets is already at 300 degrees. Adding another offset pushes it over the limit. Plan the conduit route to stay within the 360-degree maximum, or add a pull point (junction box or conduit body) where needed.
Maximum total bends between pull points = 360°
Count ALL bends, not just 90s:
• Each 90° bend = 90°
• Each offset = 2 × offset angle (e.g., 30° offset = 60° total)
• Each 3-point saddle = center angle + 2 × side angle
• Each kick = kick angle
Exceeding 360° makes wire pulling extremely difficult or impossible.
NEC Conduit Fill Calculator
Calculate NEC Chapter 9 conduit fill for mixed conductor types. Check percent fill against code limits, get violation flags, and find the next size up recommendation.