Formula Used
All developed lengths follow the conduit centerline. Custom shoe data overrides every built-in planning value.
Saddle shrink and multi-bend layouts are planning approximations. Field calibration controls the final bend marks.
Common Offset Reference
| Bend angle | Multiplier | Shrink per unit offset | Typical use |
|---|---|---|---|
| 10° | 5.7588 | 0.0875 | Long, shallow offset |
| 15° | 3.8637 | 0.1317 | Long, shallow offset |
| 22.5° | 2.6131 | 0.1989 | General field offset |
| 30° | 2.0000 | 0.2679 | General field offset |
| 45° | 1.4142 | 0.4142 | Compact offset with greater bend severity |
| 60° | 1.1547 | 0.5774 | Compact offset with greater bend severity |
How to Use This Calculator
- Select the project unit, EMT size, and bender type.
- Enter verified take-up, radius, and gain values when available.
- Add every bend in the order encountered from the conduit start.
- Enter straight distance before each bend and required geometry.
- Set stock length, waste, fittings, costs, and rounding preferences.
- Calculate, then review warnings and the complete marking schedule.
- Confirm marks with a test bend before producing repeated assemblies.
Worked Examples
| Example | Inputs | Main result | Field check |
|---|---|---|---|
| Six-inch offset | 30° bends, six-inch rise | 12-inch mark spacing; about 1.61-inch shrink | Confirm shoe arrow and spring-back |
| Rolling offset | Six inches horizontal and eight inches vertical | Ten-inch true offset before angle multiplier | Verify rotation plane before bending |
| Stub-up | 18-inch stub, six-inch take-up | Mark at 12 inches from the end | Check actual bender take-up first |
| Segmented 90° | 24-inch radius, six segments | 15° per segment | Keep every segment aligned consistently |
Common Bending Mistakes
- Using a generic take-up instead of the actual shoe value.
- Measuring from inconsistent conduit ends or reference faces.
- Ignoring shrink while locating the first offset mark.
- Reversing bend direction during a multi-plane rolling offset.
- Placing marks too closely for the selected shoe geometry.
- Forgetting coupling, connector, and trimming allowances.
- Applying outside dimensions where centerline dimensions are required.
Frequently Asked Questions
Does the calculator replace a bender chart?
No. Manufacturer marks and verified field measurements remain the primary reference.
What is conduit take-up?
Take-up is the deduction used when locating a stub-up bend mark.
What is bend gain?
Gain describes length saved when a rounded bend replaces a sharp corner.
Why does an offset shrink the run?
The angled path changes the endpoint location along the original straight axis.
How is a rolling offset measured?
Horizontal and vertical displacements form a right triangle producing true offset.
Can custom bend angles be entered?
Yes. Each bend accepts a custom angle and optional custom radius.
Can several bends share one conduit?
Yes. Add bends sequentially and review spacing or overlap warnings.
How are stock sticks estimated?
The calculator divides planned material by stock length and rounds upward.
Does the PDF button create a report?
Yes. It creates a concise project summary and bend marking schedule.
Why can actual bends differ?
Shoe geometry, spring-back, technique, and conduit variation affect final dimensions.
What should be checked before installation?
Verify dimensions, clearances, support locations, pull points, and project requirements.
Important Field Disclaimer
This calculator supports estimating and bend planning. Verify bender data, conduit dimensions, clearances, workmanship limits, and applicable project requirements before fabrication or installation.