90-Degree Bend Calculator
The 90-degree bend, also called a stub-up, is one of the most common bends in conduit work. You measure from the end of the conduit, subtract the deduct for your bender, and place your mark. This calculator gives you the exact mark position, deduct, and gain for any conduit type and size.
How to Make a 90-Degree Stub-Up
Start by deciding your stub-up height, which is the distance from the floor or surface to the top of the conduit after bending. Look up the deduct for your conduit size and bender, then subtract the deduct from the stub-up height. The result is where you place your mark, measured from the end of the conduit. Line the mark up with the bending point on your bender and make the bend.
Mark = Stub-Up Height − Deduct
Deduct depends on conduit type and size
Deduct Values by Conduit Size
| Conduit Size | EMT Deduct | IMC Deduct | Rigid Deduct |
|---|---|---|---|
| 1/2" | 5" | 5.5" | 5" |
| 3/4" | 6" | 7" | 6" |
| 1" | 8" | 9" | 8" |
| 1-1/4" | 11" | 11.5" | 11" |
| 1-1/2" | 13" | 14" | 13" |
Frequently Asked Questions
What is the deduct for a 90-degree conduit bend?
The deduct for a 90-degree bend depends on the conduit type and size. For EMT conduit, common deducts are 5 inches for 1/2 inch, 6 inches for 3/4 inch, and 8 inches for 1 inch conduit. IMC and Rigid conduit have different deduct values. The deduct is subtracted from the desired stub-up height to determine where to place your mark on the conduit.
How do I calculate the mark for a 90-degree stub-up?
To calculate the mark position for a 90-degree stub-up, subtract the deduct from your desired stub-up height. For example, if you want a 12-inch stub using 1/2 inch EMT with a 5-inch deduct, your mark is 12 minus 5 which equals 7 inches from the end of the conduit.
What is gain in a 90-degree conduit bend?
Gain is the extra length of conduit saved when making a 90-degree bend because the bend follows a curve rather than a sharp corner. It is calculated as twice the bending radius minus the deduct. Gain matters when calculating the total cut length of conduit needed for a run that includes 90-degree bends.