What is the average growth rate of nails in adults?

• A. 1/8 inch per month
• B. 1/4 inch per month
• C. 1/16 inch per month
• D. 1/2 inch per month

Answer: (A)

Nail growth is driven by the nail matrix at the base, where new keratinized cells form and push the nail outward. In adults, fingernails typically grow about 3 millimeters per month, which is roughly 1/8 inch. This rate is the standard figure many nail technicians use because it matches what you see in practice: nails lengthen steadily, though the exact pace can vary with age, health, and nutrition. Toenails grow more slowly, often around 1 millimeter per month. So the common, reliable estimate to rely on for adults is about 1/8 inch per month.