Enter hole and shaft tolerance data
The page uses a single-column flow. The calculator fields switch to three columns on large screens, two on medium screens, and one on mobile.
Example data table
These example values show how tolerance combinations change the final fit classification.
| Nominal | Hole Limits | Shaft Limits | Minimum Clearance | Maximum Clearance | Fit Type |
|---|---|---|---|---|---|
| 50.000 mm | 50.000 to 50.035 | 49.980 to 49.995 | 0.005 mm | 0.055 mm | Clearance Fit |
| 40.000 mm | 40.000 to 40.018 | 39.995 to 40.006 | -0.006 mm | 0.023 mm | Transition Fit |
| 25.000 mm | 25.000 to 25.010 | 25.012 to 25.020 | -0.020 mm | -0.002 mm | Interference Fit |
Formula used
Interpretation rules:
If both clearance values are positive, the result is a clearance fit.
If both clearance values are negative, the result is an interference fit.
If one value is positive and the other is negative, the result is a transition fit.
How to use this calculator
1. Select the basis label and working unit for your inspection task.
2. Enter the nominal size and both deviations for the hole.
3. Enter the lower and upper deviations for the shaft.
4. Add measured hole and shaft values if you want a QC pass check.
5. Press Calculate Fit to place the result block above the form.
6. Review the limit sizes, allowance, fit spread, and classification.
7. Use the Plotly graph to compare hole and shaft tolerance boundaries visually.
8. Export the summary with the CSV or PDF buttons for records, audits, or shop-floor communication.
FAQs
1. What is allowance in a hole and shaft fit?
Allowance is the difference between the smallest hole and the largest shaft. It is the minimum clearance value and may be negative for interference designs.
2. Why can the minimum clearance be negative?
A negative value means the shaft can be larger than the hole at maximum material limits. That condition indicates interference for at least some assemblies.
3. What is the difference between tolerance and fit?
Tolerance describes the permitted size variation of one feature. Fit describes the functional relationship between hole and shaft sizes after both tolerances combine.
4. When should I use a transition fit?
Use a transition fit when alignment matters and only slight clearance or interference is acceptable. It suits parts requiring accurate location without extreme press force.
5. Can I use measured dimensions for inspection decisions?
Yes. Enter actual hole and shaft values to compare them against calculated tolerance limits. The calculator then reports whether each measured dimension stays within tolerance.
6. Does the calculator support inch and metric units?
Yes. You can work in millimeters or inches. The result table also shows secondary reference values so teams can compare both systems quickly.
7. How does the graph help quality control teams?
The graph shows hole and shaft limit sizes side by side. This makes overlap, clearance room, and interference risk easier to review during inspections.
8. Is this calculator a replacement for full fit standards?
No. It is a practical calculation tool for tolerance analysis. Use your applicable drawing limits and relevant standards when making production or compliance decisions.