This engineering reference tool simplifies calculating ISO standard tolerances for mechanical design and manufacturing. It provides instant calculations for hole and shaft dimensions, with support for multiple units and a user-friendly interface.






212+ iOS apps curated and reviewed
Every iPhone needs a few good tolerance apps. We benchmark 212+ of them on App Store rating, freshness, and pricing, then surface the standouts so you don't have to scroll the App Store yourself.
| # | App | Price | Rating | Ads | In-App Purchases | Updated | |
|---|---|---|---|---|---|---|---|
| 1 | Free | — | No | No | Sep 2026 | ||
| 2 | Free | 5.0★ (2) | Yes | No | Aug 2026 | ||
| 3 | Free | — | Yes | Yes | Sep 2026 | ||
| 4 | Free | 4.8★ (5.8K) | No | Yes | Nov 2026 | ||
| 5 | Free | — | Yes | Yes | Nov 2026 | ||
| 6 | Free | 5.0★ (2) | Yes | No | Aug 2026 | ||
| 7 | Free | — | No | No | Oct 2026 | ||
| 8 | Free | — | No | No | May 2026 |






This engineering reference tool simplifies calculating ISO standard tolerances for mechanical design and manufacturing. It provides instant calculations for hole and shaft dimensions, with support for multiple units and a user-friendly interface.






Calculates engineering tolerances for various mechanical components based on ISO and ANSI standards. It determines size limits, deviations, and fit types for holes and shafts, offering schematic representations of fits.




