BendMarks Blog

How to bend offsets, saddles and stub-ups, size conductors for voltage drop, and pass fill and box-fill checks, explained with the actual formulas.

how to bend a conduit offset

How Do You Bend a Conduit Offset?

To bend an offset, multiply the offset depth by the angle multiplier for mark spacing, then add shrink so the run lands on target. Worked numbers for 30 and 45 degrees.

Read the guide → June 9, 2026
conduit bend deduct chart

What Is the Deduct on a Conduit Bend Chart?

The deduct, or take-up, is how far back to set the bender for a 90. Standard EMT deducts are 5, 6, 8 and 11.5 inches, with worked stub-up examples.

Read the guide → June 2, 2026
three point saddle

How Do You Bend a Three-Point Saddle?

A three-point saddle uses a 45 degree center bend and two 22.5 degree wings. Outer marks sit 2.5 times the depth from center, with shrink added.

Read the guide → May 26, 2026
voltage drop formula

What Is the Voltage Drop Calculation Formula?

Single-phase voltage drop is 2 times K times I times L over circular mils; three-phase uses 1.732. Copper K is 12.9, aluminum 21.2, with NEC 3 and 5 percent targets.

Read the guide → May 19, 2026
conduit fill calculation

How Do You Calculate Conduit Fill?

Conduit fill caps conductor area at 53, 31 or 40 percent of the pipe's interior by conductor count. Sum areas from NEC Table 5 against Table 4.

Read the guide → May 12, 2026
box fill calculation

How Do You Calculate Box Fill?

Box fill sums conductor, device, clamp and ground volume allowances from NEC Table 314.16(B) against the box's listed cubic inches, with worked counts.

Read the guide → May 5, 2026
conduit bending multipliers

What Are the Conduit Bending Multipliers by Angle?

Conduit bending multipliers are 6, 2.6, 2, 1.4 and 1.2 for 10, 22.5, 30, 45 and 60 degrees, with the shrink for each. Multiply offset depth by the multiplier for mark spacing.

Read the guide → April 28, 2026
how to bend a 90 degree

How Do You Bend a 90 Degree Stub-Up?

Bend a 90 degree stub-up by marking the finished height minus the bender deduct, setting the arrow on the mark, and pulling a full 90. EMT deducts are 5, 6 and 8 inches.

Read the guide → April 21, 2026