The first surprise of EMT sizing: trade size is not the actual diameter. "1/2-inch EMT" is neither 1/2" outside nor 1/2" inside — it is a nominal name, and the real dimensions are bigger. Keep this chart on the truck and stop guessing which bender fits which stick.
| Trade size | Outside diameter | Inside diameter | Wall thickness |
|---|---|---|---|
| 1/2" | 0.706" | 0.622" | 0.042" |
| 3/4" | 0.922" | 0.824" | 0.049" |
| 1" | 1.163" | 1.049" | 0.057" |
| 1-1/4" | 1.510" | 1.380" | 0.065" |
| 1-1/2" | 1.740" | 1.610" | 0.065" |
| 2" | 2.197" | 2.067" | 0.065" |
EMT is also made in 2-1/2" through 4" trade sizes; confirm exact diameters against the manufacturer's spec sheet before laying out large runs, since tolerances and coatings vary.
You pull a stick marked "3/4" off the rack and measure 0.922" across it with calipers — that confirms the chart: trade size is nominal. Grab the bender head stamped 3/4", check its 6" take-up stamp, and your stub-up math becomes mark = desired height − 6". Want an 18" stub? Mark at 12" from the end, arrow on the mark, bend to 90°.
Sizing conduit for how many wires it can legally carry (conduit fill, NEC Chapter 9 tables) is a separate calculation from bending. This site and the companion app focus on bend geometry — marks, multipliers, shrink, and calibration — and do not include a conduit fill calculator.
Try it free: Open the free conduit bending calculator — all six bend calculators, no sign-up.
Get Conduit Bend Calc on Google Play for bender calibration and Pro tools.