CalculationFit per ISO 286
Fit per ISO 286
Calculates limits of deviation, limit dimensions, clearance or interference, and fit type from nominal size, hole, and shaft tolerance zones.
How to use the result
The calculator provides values for nominal sizes over 0 to 500 mm. They are based on the tables in ISO 286-1 and ISO 286-2. Tolerance zones not defined there for the size are rejected with an explanation instead of estimating a value.
For a transition fit, minimum clearance indicates interference. Whether actual assembly has clearance or interference depends on the actual sizes. Select a clearance or interference fit when assembly or clearance must be guaranteed.
Tight tolerances cost time: an H7 hole generally requires reaming or precision boring with inspection; H6 often requires honing or grinding. Select only the tolerance needed for the function.
Formulas
maximum size = nominal size + upper deviation, minimum size = nominal size + lower deviationmaximum clearance = ES − ei, minimum clearance = EI − esfit tolerance = IT hole + IT shafthole A to H: EI = −es of the shaft with the same letter; K to N to IT8 and P to Z to IT7: ES = −ei + Δ with Δ = IT(n) − IT(n−1) Sources: DIN EN ISO 286-1; DIN EN ISO 286-2