Conduit bending calculator

Multiply the offset depth by the multiplier for your bend angle to get the distance between the two bend marks. At 30 degrees the multiplier is 2, so a 6 inch offset needs marks 12 inches apart. The pipe also shrinks, by 1/4 inch per inch of offset at 30 degrees, so add 1 1/2 inches to your first mark.

The common bender chart values are: 10 degrees, multiplier 6 and 1/16 inch shrink per inch of offset; 22.5 degrees, 2.6 and 3/16 inch; 30 degrees, 2 and 1/4 inch; 45 degrees, 1.4 and 3/8 inch; 60 degrees, 1.2 and 1/2 inch. The exact values are 1 divided by the sine of the angle.

A 3-point saddle uses a 45 degree center bend and two 22.5 degree outer bends. Put the center mark over the obstruction, then place the outer marks on each side at 2.5 times the obstruction height from the center mark. The calculator shows the marks and the shrink.

Take-up is the length the bender adds as it makes a 90 degree bend. Subtract it from the stub height you want and mark the pipe that far from the end, then line up the bender arrow with the mark. Typical hand-bender take-up is 5 inches for 1/2 inch EMT, 6 inches for 3/4 inch and 8 inches for 1 inch.

A rolling offset moves the pipe up and sideways at the same time. The true offset is the diagonal, the square root of rise squared plus roll squared. Bend it as a normal offset of the true offset, rotating the pipe in the bender by the roll angle between the two bends.