Three chart methods, one layout tool
The offset mode multiplies height by the IHSA angle factors for mark spacing and approximate shrink. Both outputs use the selected length unit. It uses the chart's fractional shrink values directly rather than the separately rounded decimal equivalents.
The segment mode uses developed length D = 1.57r, gain G = 0.43r, centre mark C = riser height − G/2, and spacing s = D/15. The marks are C − 7s through C + 7s. All fifteen shots are 6°. Radius and riser height use conduit centre-line measurements.
The three-bend saddle mode follows the Klein Angle Setter guide's six height rows (1–6 in.). A 45° centre uses two 22.5° returns; a 60° centre uses two 30° returns. It adds the row's shrink to the distance to the obstruction centre, then places return marks the table distance to either side. Metric dimensions are exact conversions of the selected inch row, not a separate metric chart.
Worked examples
A 100 mm offset with two 30° bends gives 200 mm between marks and about 25 mm shrink using the chart. The same method for a 6 in. offset gives 12 in. between marks and about 1.5 in. shrink.
For a 1000 mm centre-line radius and 1500 mm riser height, the segment model gives D = 1570 mm, G = 430 mm, centre mark 1285 mm and spacing about 104.667 mm. The first and last marks are about 552.333 and 2017.667 mm from the reference end. Keep unrounded values during layout calculations; round marks only to a precision the tool and measurement can support.
For the 4 in. (101.6 mm) saddle height row with a 45° centre, spacing is 10 in. and shrink is 3/4 in. At an obstruction-centre distance of 30 in., the three marks are 20.75, 30.75 and 40.75 in. From an equivalent 762 mm reference distance, they are 527.05, 781.05 and 1035.05 mm.
Confirm before marking conduit
This tool does not apply a bender-specific take-up, radius correction or springback allowance. The saddle mode supports only the listed Klein rows and angle pairs. This tool does not resolve other saddle patterns, rolling/parallel offsets, equipment clearances, separate fitting dimensions or a complete conduit cut length. Confirm that the selected method is suitable for the actual bender and material before using its dimensions.
Changing layout or units clears dimensional inputs and the old result. Inputs and calculated marks stay in the page and are not saved or transmitted. The calculator makes no installation or code-compliance decision.
Common questions
Why can a trigonometric calculator give different offset dimensions?
This mode follows rounded trade-chart factors. It does not claim those factors are exact cosecants or exact shrink geometry. Choose the method appropriate to your layout and confirm it against the bender instructions.
Does shrink tell me where to put the first offset mark?
No. It estimates the reduction in the run's forward reach. Locating marks relative to an obstruction depends on the measurement direction, bend radius and bender reference.
Can I change the segment shot count?
This mode implements the source's fifteen-shot method only. Changing shot count changes the method and equipment setup and is not treated as an interchangeable setting.
Related tools
Sources
Infrastructure Health & Safety Association (IHSA), Electrical Construction and Maintenance Workers Safety Manual, M010, eleventh revised edition (September 2016), “Pipe Bending Charts,” printed page 152 / PDF page 160. Formula and chart checked visually and textually November 10, 2026. The adjacent equipment-specific tables and cutting/setup instructions are not implemented.
Klein Tools, Conduit Bender and Angle Setter Guide, mobile edition, English “Saddle Bend Steps” and saddle chart, single long PDF page. Table and mark definitions checked visually and textually November 10, 2026. This mode uses the mobile instructions, which explicitly place return marks on both sides of centre. It is a manufacturer layout method, not a Canadian code rule or a universal bender model.
Report a problem or suggest a source; your dimensions are not attached automatically.