- Measure the length of your hand from the wrist line to the top of your longest finger.
- Then, round the number up to the nearest knife size. For instance, if your hand has a length of 17cm (170mm or 6.7 inches), you can comfortably use a knife with a blade length of 180mm (7.1 inches).
It's not an exact science, but it gives you a good idea of whether or not a knife will suit you.
Here is a chart of what sizes of knives are available based on the blade length.