Conduit Offset Bend
30° Conduit Offset
Everything for a 30 degree offset: the multiplier, the shrink, a worked example, and the calculator, all from the same math your bender uses.
The 30° Offset Numbers
| Multiplier (bender chart, applied / exact 1/sin) | 2.0 / 2.00 |
| Shrink per inch of offset | 1/4″ (0.2500″) |
| 6″ offset: distance between bends | 12″ |
| 6″ offset: shrink to subtract | 1.5″ |
Distance between bends = offset depth × 2.0. Shrink = offset depth × 1/4″. Both bends are 30 degrees, rotated 180° apart. Bender charts print 2.0 at 30°, which the calculator applies; exact 1/sin is 2. The chart value is what the calculator applies, so its marks match the table on your bender (see the offset multiplier chart).
The Geometry of a 30° Bend
A 30 degree offset is two 30 degree bends. On a standard 3/4" EMT bender the centerline radius is 4.5″, so each 30 degree bend has a developed length of 2.36″ of conduit through the curve (developed length = radius × the angle in radians). That is the exact geometry the 3D renderer draws for this bend. For the developed length at every size and angle, see the bend radius and developed length reference.
Calculate Your 30° Offset
The calculator opens on the worked example, a 6″ offset at 30°. Enter your own offset depth for its mark spacing and shrink.
Frequently Asked Questions
What is the multiplier for a 30 degree offset?
The multiplier for a 30 degree offset is 2.0, the constant bender-manufacturer charts print, and it is what this calculator applies. Exact 1/sin(30 degrees) is the same 2.00, so at 30 degrees the chart and the geometry agree to the digit. Multiply your offset depth by the multiplier to get the distance between the two bend marks. For a 6 inch offset that is 6 x 2.0 = 12 inches between marks.
How much does a 30 degree offset shrink?
A 30 degree offset shrinks 1/4 inch for every inch of offset depth. So a 6 inch offset shrinks the run about 1.5 inches, and a 4 inch offset shrinks about 1 inches. Subtract the shrink from your measurement so the conduit ends and fittings still land where you need them.
How do you bend a 30 degree offset?
Mark the first bend where the offset should start, then measure 12 inches (for a 6 inch offset) toward the free end and mark the second bend. Bend both marks to 30 degrees, keeping the bends in the same plane and rotating the conduit 180 degrees between them so the offset lies flat. Check the depth against your target and subtract the 1.5 inch shrink when you cut or measure the run.
When should I use a 30 degree offset?
A 30 degree offset is the everyday all-around choice, with an easy multiplier of 2.0 and moderate shrink. It balances a clean, easy wire pull against a reasonable distance between bends, which is why it is the most common offset angle for general work.