Working Length Calculator
Root canal working length from radiographic measurement.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
Recommended working length (mm)
23.6
How to Use This Calculator
- Measure the Radiographic Tooth Length (mm) on the preoperative radiograph.
- Enter the Actual File Length (mm) of the instrument used for the diagnostic radiograph.
- Input the Apparent File Tip length on film (mm) and the Reference/Stopper Setting (mm).
- Review Recommended Working Length (mm) and the Ingle method calculation.
- Use the Adjusted WL from the direct method as the final working length confirmed with apex locator.
How the result changes with Apparent file length on film (mm)
| Apparent file length on film (mm) | Recommended working length (mm) |
|---|---|
| 11 | 45.5 |
| 17 | 29.26 |
| 26 | 18.96 |
| 32 | 15.31 |
What each input means
- Radiographic tooth length (mm)
- Total tooth length measured on the radiograph (reference point to apex).
- Actual file length (mm)
- Known length of the endodontic file from stopper to tip.
- Apparent file length on film (mm)
- File length as measured on the radiograph.
- Reference/stopper setting (mm)
- Rubber stopper position on the file during the radiograph.
What each result means
- Recommended working length (mm)
- Best estimate of working length considering both methods.
- Ingle method WL (mm)
- Working length calculated by Ingle's proportion method.
- Direct method WL (mm)
- Working length by direct measurement adjustment.
- Corrected tooth length (mm)
- True tooth length after magnification correction.
- Magnification factor
- Radiographic magnification factor.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersRadiographic tooth length (mm) = 23, Actual file length (mm) = 22, Apparent file length on film (mm) = 21, Reference/stopper setting (mm) = 22 = 4 input(s) provided
- Calculate Recommended working lengthRecommended working length23.6 = 23.6
- Calculate Ingle method WLIngle method WL23.6 = 23.6
- Calculate Direct method WLDirect method WL23.6 = 23.6
Engine last updated .
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