Although nails are constantly growing, different factors affect how fast.
As you know, it’s the nail matrix that is responsible for the fingernail’s growth, but what you might not know is sometimes the nail grows faster than other times. According to the mystery-solving website WonderQuest.com, the matrix makes nails constantly — from birth to death — at an average rate of 0.004 inches (0.1 mm) each day, or 1.5 inches (36.5 mm) in a year, However, the matrix doesn’t make nails at a steady rate.
Says the site: “Nails grow faster when it’s warm, when we’re young, when we apply pressure to the nails — like playing the piano or biting, cutting, filing, polishing, or scrubbing them. Nails grow slower when the matrix is short of blood, when the blood contains stuff that stunts growth (like chemotherapy material or cigarette byproducts), when we suffer malnutrition, or have a high fever.”