EMT Bending Calculator
By Andrew ·
Quick answer
EMT bending comes down to two numbers. For offsets and saddles, marks come from the multiplier (2.000 at 30°) and the shrink per inch (0.268" at 30°). For a 90, mark = stub − the bender's deduct, which grows with the size: typically 5" for 1/2" EMT and 6" for 3/4". A 20" stub in 3/4" EMT is marked at 14".
Calculator
- Results
- Distance between bends
- 8"
- Shrink
- 1 1/16" (1.07")
Worked out the textbook way, from the bend angle alone. BendMate also uses your bender’s radius, deduct and shoe.
Typical hand bender deduct, EMT
| Size | Deduct |
|---|---|
| 1/2" EMT | 5" |
| 3/4" EMT | 6" |
| 1" EMT | 8" |
| 1-1/4" EMT | 11" |
One rule for each bend
| Bend | Rule | What depends on the size |
|---|---|---|
| Offset | Marks = height × multiplier | Only the shoe’s radius, slightly; the angle sets the marks |
| 3-point saddle | Outer marks about 2.5 × height | Only the shoe’s radius, slightly |
| 90° stub-up | Mark = stub − deduct | The deduct, which grows with the size |
| Kick | Mark = kick × multiplier | The deduct of its 90 |
That is why EMT is the easy conduit to learn. The geometry of an offset is the same in 1/2" and 1-1/4"; what changes with the size is how much the bender takes up in the 90.
Deducts by EMT size
Larger EMT needs a larger shoe with a bigger radius, and the conduit itself is fatter, so a larger size takes up more conduit in every 90. The deduct is what you subtract from the stub to allow for it.
- 1/2" EMT: typical hand bender deduct of 5"
- 3/4" EMT: typical hand bender deduct of 6"
- 1" EMT: typical hand bender deduct of 8"
- 1-1/4" EMT: typical hand bender deduct of 11"
Worked example: a 20" stub in 3/4" EMT
- Stub length
- 20"
- Deduct
- 6"
- Offset
- 4" at 30°
- Mark for the 90
- 20" − 6" = 14"
- Offset marks apart
- 8"
- Offset shrink
- about 1 1/16"
- Mark the 90 at 14" from the end, put it on the arrow with the hook toward the stub end, and pull the 90.
- Lay out the offset marks 8" apart further along the conduit.
- Bend the first offset mark to 30°, roll the conduit half a turn and bend the second the same.
- Sight along the finished conduit for a flat, parallel offset in one plane before it goes in.
EMT bending habits that save conduit
- Mark all the bends on one stick before you start, and check the marks against a tape.
- Keep the total of bends between pull points inside the NEC limit for EMT (the equivalent of four quarter bends, 360 degrees).
- Keep the pull square to the bender. EMT is thin-walled, and a twisted pull can kink it.
Putting the size into the numbers
Charts give the multiplier and a typical deduct. In BendMate the same math accounts for your bender’s radius and deduct for each EMT size, so the 1/2" and 1-1/4" marks come out the way your bender really bends them.
Get the marks for your bender
BendMate works this out from your bender’s radius and deduct, flags a bend that won’t work, and shows you every mark.
Common questions
How do you calculate bends in EMT?
For an offset, multiply the height by the multiplier for the angle and mark that far apart. For a 90, subtract the bender’s deduct from the stub length and mark there.
What is the deduct for 3/4 inch EMT?
A typical hand bender takes 6" for 3/4" EMT. It varies a little between makes, so use the figure on yours.
Is EMT bent differently from rigid conduit?
The offset and saddle geometry is identical. The difference is the shoe: EMT is bent on a hand bender up to 1-1/4", while rigid and IMC use their own shoes with their own radius and deduct.
How many bends can EMT have between boxes?
No more than the equivalent of four quarter bends, 360 degrees in total, between pull points. Offsets and kicks count towards that total.