How much, in centimeters, would the average human fingernail grow in one year?

Nails grow at an average rate of 0.1 mm/day (1 cm every 100 days) [1]. Fingernails require 4 to 6 months to regrow completely. Toenails require 12 to 18 months. Actual growth rate is dependent upon age, season, exercise level, and hereditary factors.