Electrical Calculator

Conduit Bending Calculator

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How to Use This Calculator

1. Choose your bend type by clicking one of the seven tabs above the calculator. Each tab shows the inputs relevant to that specific bend.
2. Select your conduit size by picking the EMT size from the dropdown. The calculator automatically loads the correct take-up, radius, and gain for your bender.
3. Enter your measurements: the offset height, stub length, saddle depth, or other values for your bend. Use the angle dropdown to pick standard bending angles.
4. Read your results in the right panel, which shows an SVG diagram of the bend with mark positions, key measurements, shrink, and developed length. All values update instantly as you change inputs.
5. Check the math by clicking “Show the math” to see the formula and step-by-step calculation for every result.

How to Calculate Conduit Bends

Conduit bending is one of the most hands-on skills in the electrical trade. Whether you are a first-year apprentice learning to make your first offset or a journeyman running complex stub-and-kick combinations, the underlying math is the same. Every bend starts with trigonometry: the relationship between angles, heights, and the travel distance along the conduit. A hand bender applies mechanical force at a specific radius to create a smooth arc in the EMT. The bender shoe is designed so that the mark on the conduit (aligned with the arrow on the shoe) produces a predictable result when you apply the correct technique.

Four mechanical constants define every hand bender: take-up, radius, gain, and deduct. Take-up is the distance from the bender's arrow to the back of a completed 90-degree bend. Radius is the centerline bend radius, which determines how tight the curve is. Gain is the material saved by bending instead of using a fitting: a 90-degree bend shortens the conduit run compared to two straight pieces joined at a right angle. Deduct (equal to take-up for standard benders) is what you subtract from the stub height to find the mark position. These values vary by conduit size and manufacturer, but the standard EMT hand bender values taught in trade schools and published in manufacturer bending guides are consistent across major benders like Ideal, Klein, and Greenlee. The NEC does not set take-up or gain; it sets the minimum bend radius in Chapter 9, Table 2.

Offset Bends

An offset bend moves the conduit path from one plane to a parallel plane at a specified distance. This is the most common bend in commercial and residential work. You need offsets to clear obstructions, transition from surface-mount to recessed runs, or navigate around structural members. An offset consists of two equal bends in opposite directions, separated by a calculated distance called the travel.

The math is straightforward. The travel (distance between marks) equals the offset height divided by the sine of the bend angle: Travel = Height / sin(Angle). For the most common 30-degree offset, sin(30°) = 0.5, so the multiplier is 1/0.5 = 2.0. Multiply the offset height by 2 and that is your mark spacing. A 4-inch offset at 30 degrees means your marks are 8 inches apart.

Shrink is the hidden cost of every offset. When you bend the conduit into an offset, the overall length from start to end becomes shorter than a straight piece would be. You must account for shrink when measuring from a reference point. The shrink per inch of offset height depends on the angle: 1/4 inch per inch at 30 degrees, 3/8 inch per inch at 45 degrees. For that 4-inch offset at 30 degrees, shrink = 4 × 1/4" = 1 inch. If your obstruction is 24 inches from the end of the conduit, your first mark goes at 24 − 1 = 23 inches.

The angle choice involves trade-offs. Smaller angles (10°, 15°) produce gentler bends with less shrink but require much more space between marks. A 4-inch offset at 10 degrees requires 23 inches of travel, compared to 8 inches at 30 degrees. Larger angles (45°, 60°) pack tight but increase shrink and make wire pulling harder. The 30-degree offset is the industry standard because it balances compact spacing, manageable shrink, and easy math.

Saddle Bends

Saddle bends let conduit pass over an obstruction (like another conduit, a pipe, or a structural beam) and return to the original plane. There are two types: 3-point saddles and 4-point saddles.

A 3-point saddle uses three bends: a center bend at the full angle and two outer bends at half the center angle. The center bend pushes the conduit up over the obstruction, and the two outer bends bring it back down. The most common configuration is a 45-degree center bend with 22.5-degree outer bends. The spacing from the center mark to each outer mark equals the saddle depth divided by the sine of the outer angle, the same multiplier used for offsets: Spacing = Depth / sin(Outer Angle). For a 3-inch saddle at 45 degrees center, the outer angle is 22.5 degrees and the spacing is 3 / sin(22.5°) = 3 × 2.61 = 7.84 inches from center to each outer mark. Many field charts round the multiplier to 2.5, which gives 7.5 inches.

A 4-point saddle uses four bends of equal angle to create a trapezoidal profile. This is preferred when you need to maintain the elevated path for some distance, for example when passing over a wide obstruction. The conduit rises, travels flat at the elevated height, and then descends. Four-point saddles are more complex to execute but produce a cleaner result when the obstruction is wider than about 4 inches.

90-Degree Stubs and Back-to-Back 90s

The 90-degree stub-up is the foundational bend. You use it to transition from a horizontal run along the floor or ceiling to a vertical run going up or down into a box, panel, or junction. The calculation is the simplest of all bends: mark the conduit at the stub height minus the bender's take-up. For a 12-inch stub with a 1/2" EMT bender (take-up = 5 inches), your mark goes at 12 − 5 = 7 inches from the end of the conduit.

The deduct method is how most electricians think about 90-degree bends. Deduct equals the take-up. Measure from the end of the conduit, subtract the deduct (take-up), and place your mark at that point. The end of the conduit becomes the stub, and the mark aligns with the bender arrow. The key concept that makes this work is gain. A 90-degree bend creates a shorter path than two straight pieces meeting at a right angle. The gain for 1/2" EMT is 2.42 inches measured to the outside corner. When calculating developed length (total conduit needed), add the run dimensions measured to the outside corner and subtract the gain for each 90.

Back-to-back 90s are two 90-degree bends facing each other, creating a U-shape. They are used for stub-ups into parallel junction boxes, conduit runs that need to reverse direction, or mounts that need two vertical drops at a set distance. The first bend is straightforward: stub minus take-up. For the second bend, you flip the conduit, measure the distance from the back of the first bend, and align the star point there. Expressed from the end, that mark is First Stub + Distance − Gain. The gain deduction is critical. Failing to subtract the gain for each bend is the number-one error apprentices make on back-to-back 90s, and it produces a conduit that is consistently too long. See the back-to-back 90 page for the star-point method step by step and marks by size.

Kick with 90

A kick with 90 (sometimes called a “kick 90”) combines a standard 90-degree stub-up with a small-angle offset at the top. This is the most popular advanced bend in commercial electrical work. You use it when a conduit needs to stub up from a horizontal run and then immediately offset to align with a box, panel, or another conduit rack that is not directly above the stub point.

The calculation treats the two bends independently. First, calculate the 90-degree mark just like a standard stub-up: stub height minus take-up. Then calculate the kick bend using the offset formula: kick travel = kick height / sin(kick angle). The kick mark goes at the 90-degree mark plus the kick travel. The most common kick angles are 10, 15, and 22.5 degrees: just enough offset to clear an obstruction without adding excessive degrees to the conduit run.

The trick with kick 90s is bending order. Always make the kick (the smaller bend) first, then flip the conduit and make the 90-degree bend. If you make the 90 first, it becomes very difficult to get the kick angle in the right orientation. Experienced benders also account for the kick's shrink when positioning the overall conduit, though at small angles (10–15 degrees) the shrink is minimal.

Anti-Dog Math: The 360-Degree Rule

NEC Section 358.26 (for EMT), 342.26 (for IMC), and 344.26 (for RMC) all state the same rule: conduit runs between pull points shall not contain more than the equivalent of 360 degrees of total bends. This is the “anti-dog-leg” rule. It prevents conduit runs that are so twisted that pulling wire becomes impractical or risks damaging conductor insulation.

Every bend in a run counts toward the 360-degree total, in any direction. A 90-degree stub uses 90 degrees. An offset at 30 degrees uses 60 degrees (two 30-degree bends). A 3-point saddle at 45 degrees center uses 90 degrees total (45 + 22.5 + 22.5). A kick 90 with a 22.5-degree kick uses 112.5 degrees (90 + 22.5). Four standard 90-degree bends in a single run exactly reach the 360-degree limit.

Practical planning requires tracking your bend budget as you lay out a run. A common commercial run might include an offset (60°), two 90s (180°), and a saddle (90°). That is 330 degrees, just under the limit. If you need to add another offset, you must install a pull box to create a new pull point. Good conduit layout minimizes total bends, uses the shortest paths, and places pull boxes strategically to stay within the 360-degree limit while keeping wire-pulling tension manageable.

Charts and Reference Tables

The offset multiplier and shrink by angle, the 90-degree take-up and deduct by size, and the shrink chart each have a full table worked for every angle and conduit size. They live on their own pages so you can pull up exactly the one you need:

Worked Examples

Example 1: 4-Inch Offset at 30 Degrees in 1/2" EMT

Example 2: 12-Inch Stub-Up in 3/4" EMT

Example 3: 10-Inch Stub with 22.5-Degree Kick, 3-Inch Rise in 1/2" EMT

Frequently Asked Questions

Bending References

Dedicated reference pages with complete charts, worked examples, and FAQs for each bend family.

Bending by Conduit Size

Take-up, deduct, gain, and stub marks for a specific EMT size, with the calculator pre-set.

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