EMT 90-Degree Deduction Chart

The deduct for 1/2 inch EMT on a standard hand bender is 5 inches. Measure your stub height, subtract 5 inches, and place your mark at that distance from the end of the conduit. For a 12-inch stub, the mark goes at 12 - 5 = 7 inches. Align the mark with the arrow on the bender shoe and bend to 90 degrees.

The take-up for 3/4 inch EMT is 6 inches on a standard hand bender. Take-up is the distance from the bend mark (at the bender arrow) to the back of the finished 90 degree bend. For 1 inch EMT the take-up is 8 inches, and for 1-1/4 inch EMT it is 11 inches. These values are stamped on most Ideal, Klein, and Greenlee bender shoes.

On standard EMT hand benders, yes: the deduct you subtract from the stub height equals the take-up of the shoe. The two terms describe the same constant from different directions. Take-up describes what the shoe consumes to form the bend; deduct describes what you subtract from your measurement to find the mark. Some manufacturers print one term, some the other.

Gain is the conduit you save by bending a 90 instead of joining two straight pieces at a right angle. Because the bend cuts the corner, the conduit path is shorter than the two legs measured to the outside corner. Measured to the outside corner the way a tape reaches it, gain for standard EMT benders is 2.42 inches for 1/2 inch, 2.85 inches for 3/4 inch, 3.63 inches for 1 inch, and 4.62 inches for 1-1/4 inch. Use gain when figuring the total cut length of a run with 90s, including back-to-back 90s.

Subtract the 5-inch deduct from the 12-inch stub height and mark the conduit 7 inches from the end. Slide the conduit into the bender with the mark at the arrow, keep foot pressure on the heel, and pull to 90 degrees using the level vial or a torpedo level on the vertical leg. The end of the conduit will sit 12 inches above the floor of the bend.

Mark the conduit 12 inches from the end. The first mark for any stub-up is the stub height minus the deduct: 20 - 8 = 12 inches. Notice this uses the deduct the problem gives you, so it holds for any conduit and any bender, EMT or RMC, whatever the shoe's deduct happens to be. Line the mark up with the arrow and bend to 90 degrees, and the end sits 20 inches above the bend.

The values here are the standard constants for full-size EMT hand benders from major manufacturers (Ideal, Klein, Greenlee). Compact shoes, aluminum vs. iron heads, and worn shoes can vary by a fraction of an inch, and site-made jigs vary more. Always verify with a test bend: bend a scrap piece to 90, measure from your mark to the back of the bend, and use that measured take-up for the rest of the job.

Four. NEC 358.26 limits EMT to 360 degrees of total bends between pull points, and four 90 degree bends equal exactly 360 degrees. Every bend counts toward the total, including offsets and saddles, so a run with a single 30 degree offset (60 degrees) can only fit three 90s (270 degrees) before it needs a pull box or conduit body.