On average, it takes about 5 to 6 months for a fingernail to grow one inch, and roughly 12 to 18 months for a toenail to grow the same length. This is based on typical growth rates: fingernails grow around 3 to 4.5 millimeters (about 0.1 to 0.18 inches) per month, while toenails grow more slowly, at roughly 1 to 1.6 millimeters per month.
These figures are averages, and actual growth speed varies considerably from person to person and even from finger to finger. The middle finger nail typically grows fastest, while the thumbnail tends to grow slowest. Several factors influence nail growth rate, including:
- Age — nail growth slows down as people get older
- Sex — some studies suggest men's nails grow slightly faster than women's
- Season — nails often grow faster in summer than in winter
- Dominant hand — nails on your dominant hand may grow a bit faster
- Overall health and nutrition — deficiencies in protein, biotin, iron, or other nutrients can slow growth
- Pregnancy — hormonal changes often speed up nail growth temporarily
- Circulation — better blood flow to the fingertips supports faster growth
- Underlying medical conditions — thyroid disorders, psoriasis, and other conditions can affect growth rate
- Injury or nail biting — trauma to the nail bed can temporarily slow or distort growth
Nails grow from the matrix, a area of living tissue under the cuticle at the base of the nail, and the visible nail plate itself is made of dead, hardened keratin cells that get pushed forward as new cells form beneath them. Because toenails are farther from the heart and experience more pressure and less circulation stimulation than fingernails, they consistently grow at a slower pace throughout life.
If you're trying to grow out damaged or bitten nails, patience is key — visible improvement usually takes several weeks to a few months depending on how much length was lost.