ZIKO 
Tolerance Calculator
Limit deviations and fits to ISO 286 for hole and shaft – for nominal sizes up to 500 mm.
Limit deviations and fits to ISO 286 for hole and shaft – for nominal sizes up to 500 mm.
Enter a nominal size and the tolerance classes of hole and shaft – the calculator determines the limit deviations, the maximum and minimum size of both parts and the resulting fit: clearance, transition or interference fit with maximum and minimum clearance. It is based on the tables of ISO 286-1 and offers the commonly used tolerance classes of ISO 286-2 for nominal sizes up to 500 mm.
Disclaimer: The values of the tolerance calculator have been carefully calculated to ISO 286 and checked against published standard tables, but without guarantee. They are for orientation only and replace neither the applicable standard nor the specifications on the drawing. Use is at your own risk; liability is excluded unless it is based on intent or gross negligence or concerns injury to life, body or health.
Hole
Shaft
Fit
Deviations in micrometres (µm) relative to the nominal size, limits of size in millimetres. The page address contains the selected fit and can be shared as a link.
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plug gauges for holes as well as ring gauges and snap gauges for shafts in our
calibration laboratory.
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A tolerance class such as H7 consists of a letter and a number. The letter stands for the fundamental deviation, i.e. the position of the tolerance zone relative to the zero line, the nominal size. Capital letters apply to holes and other internal features, lower-case letters to shafts and other external features. The number is the tolerance grade: the higher it is, the wider the tolerance zone. Its width is given by the standard tolerance IT, which also grows with the nominal size.
With H, the tolerance zone of the hole starts exactly on the zero line and lies above it; with h, the tolerance zone of the shaft ends exactly on the zero line and lies below it. Fits with an H hole are therefore called the hole-basis system, fits with an h shaft the shaft-basis system. JS and js are symmetrical about the zero line.
Not every tolerance class is defined for every nominal size – t and T, for example, only over 24 mm, and cd, ef and fg only up to 10 mm. The calculator points this out. For threaded features, use our thread chart with thread calculator.