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General Tolerances Calculator — ISO 2768-1
Look up general tolerance values per ISO 2768-1 by tolerance class and nominal dimension. Linear and angular tolerances with full reference tables.
Results
Table 1 — Linear Dimensions (Permissible Deviations in mm)
| Range (mm) | f (Fine) | m (Medium) | c (Coarse) | v (Very Coarse) |
|---|---|---|---|---|
| 0.5 – 3 | ±0.05 | ±0.1 | ±0.2 | — |
| 3 – 6 | ±0.05 | ±0.1 | ±0.3 | ±0.5 |
| 6 – 30 | ±0.1 | ±0.2 | ±0.5 | ±1 |
| 30 – 120 | ±0.15 | ±0.3 | ±0.8 | ±1.5 |
| 120 – 400 | ±0.2 | ±0.5 | ±1.2 | ±2.5 |
| 400 – 1000 | ±0.3 | ±0.8 | ±2 | ±4 |
| 1000 – 2000 | ±0.5 | ±1.2 | ±3 | ±6 |
| 2000 – 4000 | — | ±2 | ±4 | ±8 |
Table 2 — Angular Dimensions (Permissible Deviations)
| Shorter Side (mm) | f (Fine) | m (Medium) | c (Coarse) | v (Very Coarse) |
|---|---|---|---|---|
| ≤ 10 | ±1° | ±1° | ±1°30′ | ±3° |
| 10 – 50 | ±0°30′ | ±0°30′ | ±1° | ±2° |
| 50 – 120 | ±0°20′ | ±0°20′ | ±0°30′ | ±1° |
| 120 – 400 | ±0°10′ | ±0°10′ | ±0°15′ | ±0°30′ |
| > 400 | ±0°5′ | ±0°5′ | ±0°10′ | ±0°20′ |
ℹ️ Note: ISO 2768-1 applies to all dimensions on the drawing that do not have individual tolerances specified. The tolerance class letter is placed in the title block, e.g. “ISO 2768-m”.
What Are General Tolerances?
General tolerances per ISO 2768-1 define permissible deviations for linear and angular dimensions that do not carry individual tolerance indications on a drawing. They represent normal workshop accuracy achievable with standard machining processes.
The actual dimension must fall within the range:
Tolerance Class Selection
- f (Fine) — Precision machining, tight fits. Requires careful process control.
- m (Medium) — Most commonly used. Standard machining (turning, milling, drilling).
- c (Coarse) — Rough machining, welded structures, non-critical parts.
- v (Very Coarse) — Castings, flame-cut parts, forgings.
Drawing Notation
For linear tolerances only: ISO 2768-m
Combined with geometrical tolerances (ISO 2768-2): ISO 2768-mK
This means: linear tolerance class “m” + geometrical tolerance class “K”.
⚠️ Important: General tolerances do not apply to dimensions with individual tolerances, reference dimensions (in parentheses), or dimensions governed by other standards.
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Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
