Reference Library
Pocket Watch Key Sizes
Use the chart below to find the proper pocket watch key size to wind and set your early American movement. Please note the different size specifications utilized by various regions and match available keys accordingly. When in doubt, we recommend purchasing a set of keys, offering various sizes.
Pocket Watch Key Size Calculator
Suggested Size:
| English Square Size | Key Size | Indian Square Size |
|---|---|---|
| 0.95mm | 00 | 2.00mm |
| 1.00mm | 0 | 1.90mm |
| 1.05mm | 1 | 1.80mm |
| 1.15mm | 2 | 1.75mm |
| 1.20mm | 3 | 1.65mm |
| 1.30mm | 4 | 1.60mm |
| 1.40mm | 5 | 1.50mm |
| 1.50mm | 6 | 1.40mm |
| 1.60mm | 7 | 1.30mm |
| 1.70mm | 8 | 1.20mm |
| 1.75mm | 9 | 1.90mm |
| 1.80mm | 10 | 1.05mm |
| 1.90mm | 11 | 1.00mm |
| 2.00mm | 12 | 0.95mm |