ISO Limits and Fits Calculator
Find hole and shaft tolerances, and the resulting fit, per ISO 286.
Hole (H7)
Upper deviation: +21 μm
Lower deviation: +0 μm
Max size: ⌀25.021 mm
Min size: ⌀25 mm
Shaft (g6)
Upper deviation: -7 μm
Lower deviation: -20 μm
Max size: ⌀24.993 mm
Min size: ⌀24.98 mm
Fit result
Clearance fitMax clearance: +41 μm
Min clearance: +7 μm
A negative value means interference rather than clearance.
Usage examples
Choosing a shaft tolerance for a bearing seat
When deciding between k6 or p6 for a shaft that presses into an H7 bearing bore, see the actual max/min sizes and interference right away.
Double-checking a tolerance callout before it goes on a drawing
Before writing H7/g6 or similar on a drawing, confirm whether that combination is actually a clearance fit or a transition fit.
Checking a purchased part's tolerance compatibility
Compute the actual allowable range for the tolerance class printed on a supplier's part drawing, to confirm it mates properly with the part you designed.
Frequently asked questions
What standard is this calculator based on?
It's based on ISO 286, the international standard for the ISO code system for tolerances on linear sizes and fits.
Does it support every tolerance class?
No. It covers the grades and classes used in the overwhelming majority of real mechanical design — H, G, F, E, D (clearance), K, M, N, P, R (transition/interference), and JS (symmetric). Classes like C (very loose fits) and S/U (heavy interference fits) were deliberately left out because they couldn't be confidently cross-verified against reliable published sources.
Can I use these results directly for manufacturing or inspection?
The calculation logic was cross-checked against published ISO 286 tables from multiple sources, but for safety-critical designs, confirm the final values against the official standard document or your organization's quality requirements.
How is a clearance fit distinguished from an interference fit?
If both the max and min clearance are positive, it's a clearance fit. If both are negative (interference), it's an interference fit. If one is positive and the other negative, it's a transition fit.