Conduit Bending Calculator
Professional conduit bending calculator for electrical installations. Calculate offset multipliers, shrink, stub-up take-up, and 3-point and 4-point saddle bend layouts for EMT, rigid, and flexible conduit.
Conduit Size
3/4"
Type
EMT
Deduct
"
Gain
"
Common Multipliers
10° = ×6.0 | 15° = ×3.9 | 22.5° = ×2.6
30° = ×2.0 | 45° = ×1.4 | 60° = ×1.15
Bend Radius
Minimum bend radius: "
(Based on NEC Table 300.4(B))
NEC Requirements
• Maximum 360° total bends between pull points
• Maintain minimum bend radius to prevent damage
• No more than four 90° bends in one run
Tips
• Measure twice, bend once
• Practice on scrap pieces first
• Use steady, continuous pressure
• Mark all bend points before starting
90° Bend
Standard stub-up or back-to-back bend. Use deduct to calculate marking point from end of conduit.
Offset Bend
Two bends in same plane to navigate around obstacles. Distance = Offset × Multiplier.
Back-to-Back
Two 90° bends in opposite directions. Commonly used for panel connections.
Kick (3-Point Saddle)
Three bends to go over obstacles. Center bend is twice the side bend angles.
Developed Length
Arc length of the bent section. Useful for calculating total conduit needed.
How to Calculate Conduit Bends: Step-by-Step
Accurate conduit bending prevents kinks, maintains code compliance, and ensures a professional installation. Here is how to calculate the key measurements for offset bends.
Step 1: Measure the Offset Distance
Determine how far the conduit needs to move from one plane to another. This is the perpendicular distance between the starting and ending positions. For example, clearing a 6-inch obstruction requires a 6-inch offset.
Step 2: Choose the Bend Angle
Common offset angles are 10, 22.5, 30, and 45 degrees. Shallower angles create gentler bends that are easier to pull wire through. 30 degrees is the most commonly used angle for standard offsets.
Step 3: Calculate the Distance Between Bends
Multiply the offset height by the multiplier for your angle: 6.0 for 10 degrees, 2.6 for 22.5 degrees, 2.0 for 30 degrees, and 1.4 for 45 degrees. This gives the center-to-center distance between your two bend marks.
Step 4: Mark the Conduit
Place your first mark where the offset begins. Measure the calculated distance and place the second mark. Both bends will be made at the same angle but in opposite directions.
Step 5: Account for Shrinkage
Offsets shorten the overall conduit length. The shrinkage amount depends on the angle: 1/16" per inch for 10 degrees, 3/16" per inch for 22.5 degrees, 1/4" per inch for 30 degrees, and 3/8" per inch for 45 degrees. Add this to your total conduit length.
Formula
Distance Between Bends = Offset Height x Multiplier
Where: Multiplier = 6.0 (10 deg), 2.6 (22.5 deg), 2.0 (30 deg), 1.4 (45 deg). Shrinkage per inch of offset: 1/16" (10 deg), 3/16" (22.5 deg), 1/4" (30 deg), 3/8" (45 deg)
Worked Example
Scenario: You need to bend a 6-inch offset at 30 degrees in 3/4" EMT conduit.
- Step 1: Offset distance = 6 inches
- Step 2: Chosen angle = 30 degrees (multiplier = 2.0)
- Step 3: Distance between bends = 6 x 2.0 = 12 inches
- Step 4: Mark conduit at the starting point, then 12 inches away for the second bend
- Step 5: Shrinkage = 6 x 1/4" = 1.5 inches added to the total run
Result: Place bends 12 inches apart at 30 degrees each, and add 1.5 inches to account for shrinkage in the overall run.
Conduit Offset Multiplier Chart
The offset multiplier is the number you multiply by the offset depth to find the distance between your two bend marks: Distance between bends = Offset depth × Multiplier. Each angle also has a shrink constant, the amount of conduit length "used up" per inch of offset, which you add to your measurement so the run still lands where you need it. These are the standard multipliers and shrink values every electrician memorizes.
| Bend Angle | Offset Multiplier | Shrink per Inch of Offset |
|---|---|---|
| 10° | 6.0 | 1/16" |
| 22.5° | 2.6 | 3/16" |
| 30° | 2.0 | 1/4" |
| 45° | 1.4 | 3/8" |
| 60° | 1.2 | 1/2" |
The multiplier comes from trigonometry: it equals 1 divided by the sine of the bend angle. Shallow angles like 10° spread the offset over a long distance (easier wire pulls, but needs more room), while steep angles like 45° or 60° fit tight spaces at the cost of harder pulls and more shrink.
Worked Example: 4" Offset at 30°
- Distance between marks: 4" offset × 2.0 multiplier = 8" between bend marks
- Shrink: 4" × 1/4" per inch = 1" of shrink
- Layout: Add the 1" shrink to your measurement to the first bend, then place the second mark 8" past the first
Result: Two 30° bends, 8 inches apart, with 1 inch added to the run to compensate for shrink.
3 Point Saddle Bend
A 3 point saddle lets conduit hop over a small round obstruction, most often another pipe or a small conduit crossing your run. Instead of two full offsets, it uses three bends: a single center bend that peaks over the obstruction and two smaller return bends that bring the conduit back to its original line.
Standard Method: 45° Center, 22.5° Sides
The classic 3 point saddle uses a 45° center bend flanked by a 22.5° bend on each side. Because the side bends are exactly half the center angle, the conduit returns to the same plane it started in.
Layout Rules
- Center mark: Measure to the center of the obstruction, then add 3/16" of shrink for every inch of saddle height before marking.
- Side marks: Place one mark 2.5 × the saddle height on each side of the center mark.
- Bender alignment: Most hand benders have a dedicated saddle mark, a rim notch or teardrop symbol, for the center bend. Line the center mark up with the notch, not the arrow. Use the arrow as usual for the two 22.5° side bends.
- Same plane: Keep all three bends rotated in exactly the same plane, or the saddle will corkscrew and not sit flat.
Worked Example: Saddling a 3" Obstruction
Scenario: Your EMT run crosses a 3" pipe whose center is 24" from the end of the conduit.
- Step 1: Saddle height = 3". Shrink = 3 × 3/16" = 9/16"
- Step 2: Center mark = 24" + 9/16" = 24-9/16" from the end of the conduit
- Step 3: Side marks = 2.5 × 3" = 7-1/2" on each side of the center mark
- Step 4: Bend the center mark to 45° at the bender's saddle notch
- Step 5: Flip your reference and bend each side mark to 22.5° in the opposite direction
Result: A saddle that clears the 3" pipe with the center bend landing directly over the obstruction.
4 Point Saddle Bend
A 4 point saddle is the right choice when the obstruction is wider or squared-off, think rectangular duct, structural steel, a junction box, or a wide pipe rack, where a 3 point saddle's single peak cannot span the width. A 4 point saddle is simply two equal offsets back to back: one offset up onto the obstruction, a flat section across it, and a mirror-image offset back down.
Choosing the Angles
The most common layouts use four 22.5° bends or four 30° bends. All four bends are the same angle, so each pair uses the standard offset multiplier: 2.6 for 22.5° or 2.0 for 30°. Use 22.5° when you have room to spread the saddle out; use 30° when space is tighter or you want easy math.
Layout Steps
- Step 1: Measure the obstruction height (saddle depth) and its width along the run.
- Step 2: Distance between the bends in each offset pair = obstruction height × multiplier (for example, a 4" tall duct at 30° needs 4 × 2.0 = 8" between marks 1-2 and between marks 3-4).
- Step 3: Measure to the near edge of the obstruction, add the shrink for the first offset (1/4" per inch of height at 30°, 3/16" at 22.5°), and place mark 1.
- Step 4: Place mark 2 at the multiplier distance past mark 1. Bend both to complete the first offset.
- Step 5: Place marks 3 and 4 so the flat section between the two offsets spans the full width of the obstruction, then bend the second offset in the mirror-image direction.
- Step 6: Total shrink for the saddle is double a single offset's shrink, since the conduit goes up and comes back down.
Pro Tip
Bend the first offset, set the conduit in place against the obstruction, and mark the second offset from the actual installed position when you can. Field-marking the second pair absorbs small angle errors that would otherwise leave the far side of the saddle high or low.
Stub-Up and Take-Up Deductions
A stub-up (stub 90) is the most basic bend: a 90° bend that turns the conduit up to a set height. The take-up (deduct) is the amount your bender consumes in the bend. Measure your stub height, subtract the take-up, and mark the conduit; line that mark up with the arrow on the bender and the stub will land exactly at the required height.
| EMT Size | Take-Up (Deduct) |
|---|---|
| 1/2" | 5" |
| 3/4" | 6" |
| 1" | 8" |
| 1-1/4" | 11" |
Example: For a 12" stub in 3/4" EMT, subtract the 6" take-up: mark the conduit at 12 − 6 = 6" from the end, align the mark with the bender arrow, and bend to 90°. Take-up values are stamped on most bender heads; always confirm against your specific bender.
Conduit Bending Questions & Answers
What's the standard deduct for 90-degree bends?
The deduct varies by conduit size and type. For EMT: 1/2" = 5", 3/4" = 6", 1" = 8", 1-1/4" = 11", 1-1/2" = 14", 2" = 16". For rigid conduit, add about 1" to each deduct. These are center-line radius measurements. Always verify with your bender's specifications and practice on scrap pieces.
How do you calculate offset bend measurements?
For offset bends, use the formula: Distance between bends = Offset × multiplier (the multiplier is 1 ÷ sin of the bend angle). For common angles: 10° multiplier = 6, 15° = 3.9, 22.5° = 2.6, 30° = 2, 45° = 1.4. Shrink per inch of offset: 1/16" (10°), 3/16" (22.5°), 1/4" (30°), 3/8" (45°). For a 6" offset at 30°: distance = 6 × 2 = 12", shrink = 6 × 1/4" = 1-1/2".
What is the multiplier for a 45 degree offset?
The multiplier for a 45 degree offset is 1.4. Multiply the offset depth by 1.4 to get the distance between your two bend marks, and allow 3/8 inch of shrink for every inch of offset. Example: a 5-inch offset at 45 degrees needs marks 5 × 1.4 = 7 inches apart, with 5 × 3/8" = 1-7/8" of shrink added to the overall run.
What is the multiplier for a 30 degree bend?
The multiplier for a 30 degree offset is 2.0, which makes it the most popular offset angle among electricians: the math is easy (just double the offset depth to get the distance between bends) and the shrink is a clean 1/4 inch per inch of offset. Example: a 4-inch offset at 30 degrees needs marks 4 × 2.0 = 8 inches apart with 1 inch of shrink.
How do you bend a 3 point saddle?
A 3 point saddle uses a 45° center bend with a 22.5° bend on each side. Measure the distance to the center of the obstruction and the saddle height needed. Add 3/16" of shrink per inch of saddle height to the center measurement, then mark the center point. Place the side marks 2.5 × the saddle height on each side of the center mark. Bend the center mark to 45° using the saddle notch (rim notch or teardrop) on your bender, then bend each side mark to 22.5° in the opposite direction, keeping all three bends in the same plane.
What's the difference between EMT and rigid conduit bending?
EMT (Electrical Metallic Tubing) is thinner and easier to bend, requiring less force and smaller radius bends. Rigid conduit has thicker walls and requires more force, larger radius bends, and different deduct values. EMT uses compression fittings while rigid uses threaded connections. EMT is more common for interior work, rigid for outdoor and industrial applications.
How many degrees can you bend conduit in one pull?
NEC 358.26 limits total bends to 360° (four 90° bends) between pulling points like boxes or conduit bodies. This prevents excessive stress on wire insulation during pulling. For practical installation, try to keep it under 270° when possible. Use pulling elbows, LBs, or junction boxes to break up long runs with multiple bends.
What tools do I need for conduit bending?
Basic tools: hand bender (hickey) for smaller sizes, mechanical or hydraulic bender for larger conduit, measuring tape, level, permanent marker, and reamer. For precision work: protractor, torpedo level, and conduit bending guide. Electric benders speed up production work. Always use proper PPE and check bender condition before use.
How do you prevent conduit from kinking during bends?
Use proper bending technique: steady, continuous pressure rather than jerky movements. Don't exceed the minimum bend radius for your conduit size. For hand bending, keep your foot placement consistent and apply gradual force. For mechanical benders, ensure proper alignment and use the right die. Practice on scrap pieces first, especially with larger sizes.
What's the minimum bend radius for different conduit sizes?
NEC Table 300.4(B) specifies minimum bend radii. For EMT: 1/2" = 4", 3/4" = 4.5", 1" = 5.3", 1-1/4" = 7.2", 1-1/2" = 8.2", 2" = 9.5". These are one-shot 90° bends. Field bends can have smaller radii but must not damage the conduit or significantly reduce the internal cross-sectional area. Always follow manufacturer specifications.
How do you measure and mark conduit for complex bends?
Start with accurate field measurements and a detailed sketch. Mark all bend points before bending. Use the "measure twice, cut once" principle. For multiple bends, work from a fixed reference point. Account for take-up and gain/shrink in your measurements. Consider making a cardboard template for complex shapes or repetitive bends.
What's the difference between gain and shrink in conduit bending?
Gain is the distance saved when making a 90° bend compared to using two straight pieces with an elbow fitting. Shrink is conduit length lost in offset bends. For 90° bends, gain = (2 × center-line radius) - deduct. For offsets, shrink = offset height × the shrink constant for the angle (1/4" per inch at 30°, 3/8" per inch at 45°). Understanding both helps with accurate conduit length calculations and material estimation.
How do you bend conduit in tight spaces?
In cramped areas, pre-bend conduit when possible or use mechanical benders that require less swing space. Segmented bends (multiple small bends instead of one large bend) can help navigate tight spots. Consider using flexible conduit sections, pulling elbows, or conduit bodies to reduce bending requirements. Plan your routing to minimize difficult bends in confined spaces.
What safety precautions should I take when bending conduit?
Wear safety glasses, work gloves, and steel-toed boots. Check bender condition before use - look for cracks, wear, or damage. Maintain stable footing and body position. Don't over-bend then try to bend back. Use proper lifting techniques for heavy conduit. Be aware of overhead hazards and electrical equipment. Keep work area clean and well-lit. Never use damaged or worn bending equipment.
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