How the Conduit Bending Calculator works
This calculator covers the bends electricians make with a hand bender: offsets, 90° stub-ups, back-to-back 90s, 3-point and 4-point saddles and kicks, for EMT, IMC and rigid. It gives the distance between bend marks, the shrink, the take-up and gain of a 90°, and, if you enter the distance to the obstruction, every mark measured from the conduit end with the bending order.
An offset is two equal bends. The marks are depth × multiplier apart, where the multiplier is 1 ÷ sin of the bend angle: 10° 5.759, 22½° 2.613, 30° 2.000, 45° 1.414, 60° 1.155. The bent conduit also comes up shorter, the shrink: 1/16", 3/16", 1/4", 3/8" and 1/2" per inch of depth for 10°, 22½°, 30°, 45° and 60°. A stub-up mark is the stub height minus the bender's take-up, and a 3-point saddle puts the outer marks 2½" per inch of height from the center and shrinks 3/16" per inch.
Example: a 6" offset with 30° bends to clear something 30" from the end of the conduit. The marks are 6 × 2 = 12" apart and the shrink is 6 × 1/4" = 1 1/2". The offset has to reach full depth right at the obstruction, so the second mark goes at 30 + 1 1/2 = 31 1/2" from the end and the first at 31 1/2 − 12 = 19 1/2". Bend the first mark with the arrow, then roll the conduit 180° and bend the second.
Take-up and gain vary by bender, so check the marks on yours and save your own values under My bender. When you don't type a gain, it is estimated from the take-up and the conduit's outside diameter (1/2" EMT with a 5" take-up: about 2 11/16"). If the first mark lands less than 6" from the end, the app warns that the bender can't grip there; that 6" is the app's own conservative rule, not a code or maker figure. The NEC limits the bends between pull points (see the FAQ below), and local amendments may add their own rules.
Frequently asked questions
What is the multiplier for a 30 degree conduit offset?
2. Space the two bend marks twice the offset depth apart: a 6" offset gets marks 12" apart. The shrink for 30° bends is 1/4" per inch of depth, so a 6" offset shrinks 1 1/2".
How much shrink for a conduit offset?
Per inch of offset depth: 10° 1/16", 22½° 3/16", 30° 1/4", 45° 3/8", 60° 1/2". Multiply by the depth: a 10" offset with 45° bends shrinks 10 × 3/8" = 3 3/4", and its marks are 10 × 1.414 = 14 1/8" apart. Add the shrink when you measure to an obstruction, because the bent conduit comes up short by that much.
How do you bend a 90 degree stub-up?
Subtract the bender's take-up from the stub height and put the bender's arrow on that mark, measured from the conduit end. A 12" stub on 1/2" EMT with a 5" take-up: mark at 12 − 5 = 7". Typical hand-bender take-ups for EMT are 5" (1/2"), 6" (3/4"), 8" (1") and 11" (1¼"); check the one on your bender.
How do you bend a 3-point saddle?
Bend 45° in the center over the obstruction and 22½° at each outer mark, 2½" per inch of saddle height from the center. Move the center mark ahead by the shrink, 3/16" per inch of height. A 2" saddle with its center 24" from the end: center mark at 24 3/8", outer marks 5" to each side at 19 3/8" and 29 3/8".
How many degrees of bends are allowed in a conduit run?
The NEC allows no more than the equivalent of four quarter bends, 360° in total, between pull points (358.26 for EMT, 342.26 for IMC, 344.26 for rigid, 352.26 for PVC). Count every bend, offsets and saddles included: a 3-point saddle adds 45° + 22½° + 22½° = 90°. Check the code edition your inspector enforces.