The rate of growth for fingernails varies enormously. As a very general guide, anything from half an inch (0.5 cm) to 4 inches or 10 cm per year can be considered normal, but growth depends on a number of factors.

First of all, are you right or left handed? The nails on the hand you use more will tend to grow more quickly (perhaps part of the overall greater strength of the dominant hand) and the nails on your longer fingers, especially the middle one, grow faster than on the little finger. That explains why all nails rarely need cutting to the same extent at the same time.

The younger and healthier you are, the faster your nails will grow, and they also grow faster in the summer than the winter. Under any conditions, though, fingernails always grow much faster than toenails and so need trimming much more often.