Conduit Bending Calculator
Lay out offsets and stub-ups without guessing. Enter an offset depth and bend angle to get the distance between bend marks and the shrink to add to your measurement, plus the mark distance for a 90° stub by EMT trade size.
Offset Bend
90° Stub-Up
Bend Marks
Offset multiplier ×2 at 30°. Stub mark = height − take-up (5" for 1/2" EMT). Confirm against your bender's marks.
How this calculator works
An offset is two equal bends that jog the run around an obstacle. The geometry is a right triangle: the distance between bend marks is the offset depth times the cosecant of the bend angle, and the shrink is how much shorter the run gets end-to-end:
distance between bends = offset depth × multiplier · shrink = offset depth × shrink/inch
90° stub: mark = stub height − take-up
The multipliers are the rounded field numbers every bender ships with — 6 at 10°, 2.6 at 22.5°, 2 at 30°, 1.4 at 45°, 1.2 at 60° — close to the true cosecants but not identical (see the table below), which is why 30° with its exact ×2 is the angle most hands default to. For a 90° stub-up, the take-up is the length the bend itself consumes: measure the stub height, subtract the take-up for the conduit size, and put the bender’s arrow on that mark. These take-up and shrink figures are bender-family practice, not code — typical for EMT hand benders — so confirm against the numbers stamped on your specific bender before committing a rack of pipe.
Worked example
A 6" offset over a beam using 30° bends, then a 12" stub-up in 1/2" EMT — the calculator’s default inputs:
- Distance between bends: 6 × 2.0 = 12.00 in between the two marks.
- Shrink: 6 × 1/4 = 1 1/2" — mark the obstacle distance, then add the shrink so the offset lands where you measured.
- Stub-up: 12 − 5 (1/2" EMT take-up) = 7.00 in from the end of the conduit to the bender arrow.
Enter the same numbers above to reproduce all three marks.
Reference: multipliers, shrink & take-up
Offset multipliers and shrink per inch of offset depth — the field numbers the calculator uses, with the exact cosecant alongside:
| Bend angle | Multiplier (field) | Exact csc θ | Shrink per inch |
|---|---|---|---|
| 10° | × 6 | 5.76 | 1/16" |
| 22.5° | × 2.6 | 2.61 | 3/16" |
| 30° | × 2 | 2.00 | 1/4" |
| 45° | × 1.4 | 1.41 | 3/8" |
| 60° | × 1.2 | 1.15 | 1/2" |
90° stub-up take-up by EMT trade size — bender-family figures; confirm against your bender’s stamped take-up:
| EMT size | Take-up |
|---|---|
| 1/2" | 5" |
| 3/4" | 6" |
| 1" | 8" |
| 1-1/4" | 11" |
| 1-1/2" | 14" |
| 2" | 16" |
Frequently asked questions
What multiplier do I use for a 30-degree offset?
Two. Distance between bends = offset depth × 2, which is why 30° is the field default — a 6-inch offset means marks 12 inches apart, no calculator needed. The full set this tool uses: 10° × 6, 22.5° × 2.6, 30° × 2, 45° × 1.4, 60° × 1.2. These are the rounded cosecant values every bender chart is built on.
How do I account for conduit shrink on an offset?
Every offset shortens the effective run, and you add that shrink to your measurement before making the first mark. Per inch of offset depth: 10° loses 1/16″, 22.5° loses 3/16″, 30° loses 1/4″, 45° loses 3/8″, and 60° loses 1/2″. Example: a 4-inch offset at 30° shrinks 1 inch — so if the obstacle is 40 inches away, mark the first bend at 41.
What is the take-up (deduct) for a 90-degree stub bend?
Take-up is what the bend itself consumes: mark distance = desired stub height − take-up, measured from the end of the conduit. Typical EMT values are 5″ for 1/2″, 6″ for 3/4″, 8″ for 1″, and 11″ for 1-1/4″ — the numbers this calculator uses. Take-up is a property of the bender shoe, not the code, so always confirm against the value stamped on your bender.
Which bend angle should I use for an offset?
Shallower angles pull easier and shrink less, but they need more room — a 6-inch offset at 10° puts the bends 36 inches apart versus 12 inches at 30°. Use 30° as the everyday default, drop to 10° or 22.5° on long feeder runs where pulling tension matters, and save 45° or 60° for tight quarters where the conduit has to get around something close. Steeper bends also add more degrees toward the code limit on the run.
How many bends does the NEC allow between pull points?
No more than 360 degrees total between pull points — boxes, conduit bodies, or fittings — per the conduit articles (358.26 for EMT, with the same rule in each raceway article). Count everything: a 90 is 90°, a 30° offset is 60°, a three-point saddle adds 90°, so four 90s max out a run with nothing left for offsets. Fewer degrees means an easier pull; verify against the code edition adopted in your jurisdiction.
Method: offset geometry (distance = depth × csc θ) with the trade’s rounded multipliers and shrink constants; 90° stub mark = desired height − bender take-up. These are bender-family practice figures — take-up varies by bender make and shoe, and larger angles bent on the same offset raise the shrink — so the marks on your bender govern. Code limits still apply to the finished run: keep the total bends between pull points within the NEC’s 360° allowance.
Bends done, check the wire path: the Conduit Fill Calculator sizes the raceway, the conduit size & fill chart has the usable areas by trade size, and the conduit bodies chart decodes the LBs and LRs at the ends of the run.