Saddle Bend Calculator

WA 3-point saddle bend carries conduit over a centered obstruction while returning the raceway to its original direction. The Saddle Bend Calculator produces the layout marks needed to place the two outside bends around a center bend: Near outside mark, Far outside mark, and Center-to-outside mark spacing.

The calculation starts with the obstruction’s clear rise and the selected Outside bend angle. The center bend is automatically twice the outside angle. With 22.5-degree outside bends, the layout uses a 45-degree center bend.

The Center mark from conduit end establishes the center bend location from one consistent conduit end. The calculator then locates each outside bend mark at an equal distance on either side of that center mark.

3-Point Saddle Geometry

A standard three-bend saddle uses:

• One center bend over the obstruction
• Two equal outside bends on each side of the center bend
• Equal center-to-outside mark spacing
• A center bend angle equal to twice the outside bend angle

For this calculator:

\(\text{Center bend angle} = 2 \times \text{Outside bend angle}\)

\(\text{Spacing multiplier} = \frac{1}{\sin(\text{Outside bend angle})}\)

\(\text{Center-to-outside mark spacing} = \text{Obstruction height} \times \text{Spacing multiplier}\)

\(\text{Near outside mark} = \text{Center mark from conduit end} - \text{Center-to-outside mark spacing}\)

\(\text{Far outside mark} = \text{Center mark from conduit end} + \text{Center-to-outside mark spacing}\)

The spacing multiplier increases as the outside bend angle becomes smaller. A shallow saddle therefore requires more distance between the center mark and each outside mark than a sharper saddle for the same obstruction height.

Calculator Inputs

Input	Electrical layout purpose
Obstruction height	The clear rise the conduit must pass over. Measure the actual height required to clear the obstruction, not the obstruction’s nominal size unless that dimension provides the required clearance.
Outside bend angle	The angle used for each outside bend. The calculator sets the center bend to twice this angle.
Center mark from conduit end	The center bend layout mark measured from the same conduit end used for all layout measurements.

The center mark is the reference point for the saddle. Changing Center mark from conduit end shifts the entire saddle along the conduit without changing its geometry. Changing Obstruction height or Outside bend angle changes the center-to-outside spacing.

Calculated Layout Marks

The calculator returns the following layout values:

Result	Use in conduit layout
Near outside mark	First outside bend mark encountered when measuring from the selected conduit end.
Far outside mark	Second outside bend mark, located beyond the center mark.
Center-to-outside mark spacing	Equal distance from the center mark to each outside mark.
Spacing multiplier	Multiplier applied to obstruction height to determine the center-to-outside mark spacing.
Center bend angle	Bend angle for the center of the saddle; twice the selected outside bend angle.
Estimated shrink	Reported allowance associated with the saddle layout. Verify the final center position on the bender and against the installed obstruction.

Calculation Example

For the displayed values:

• Obstruction height: 4 in
• Outside bend angle: 22.5 deg
• Center mark from conduit end: 48 in

The calculator determines the center bend angle:

\(2 \times 22.5^\circ = \text{45 deg}\)

It then calculates the spacing multiplier:

\(\frac{1}{\sin(22.5^\circ)} = \text{2.6131 x}\)

The center-to-outside spacing is:

\(4\text{ in} \times 2.6131 = 10.4525\text{ in}\)

The outside marks are placed equally around the 48-inch center mark:

\(48 - 10.4525 = 37.5475\text{ in}\)

\(48 + 10.4525 = 58.4525\text{ in}\)

Result	Calculated value
Near outside mark	37.5475 in
Far outside mark	58.4525 in
Center-to-outside mark spacing	10.4525 in
Spacing multiplier	2.6131 x
Center bend angle	45 deg
Estimated shrink	0.7956 in

Mark the conduit at 37.5475 in, 48 in, and 58.4525 in from the same conduit end. The two outside marks use 22.5-degree bends, while the center mark uses a 45-degree bend in the opposite direction to form the saddle.

Field Verification

The calculated marks establish the geometric layout; they do not replace bender-specific verification. Bender reference points, conduit size, conduit type, bending method, obstruction width, required clearance, and the orientation of the shoe can affect where the finished saddle lands.

Use the reported Estimated shrink when locating a saddle from an obstruction center, then verify the final center mark on the actual bender. Maintain all measurements from the same conduit end, confirm the bends stay in one plane, and check that the completed conduit clears the obstruction without introducing an unintended dogleg or misaligning the raceway.