Your fingernails grow at an of 3.47 millimeters (mm) per month, or about a tenth of a millimeter per day. To put this in perspective, the of short rice is about 5.5 mm long.

If you happen to lose a fingernail, it may take for that nail to completely grow back. The nails on your dominant hand than the rest, as do the nails on your longer fingers.

Your fingernails also during the day and during the summer.

Although it may sound like there’s no rhyme or reason to how your nails grow, there are a few basic factors that affect the speed of growth. Read on to learn more about these factors, as well as what you can do to make them grow faster.

There are a number of reasons why your nails may grow faster or slower than the average rate.

Location

The nails on your dominant hand grow faster simply because you use your dominant hand more. This increases your risk for trauma, like catching your nail on a snag or hitting your nail with a hammer.

If trauma does occur, your body naturally sends more blood and nutrients to the area to help repair it. This influx of nutrients may speed up nail growth.

The rate of growth also depends on which finger the nail is on. A found that the fingernail on your little finger grow slower than other fingernails.

Age

Being younger has also been with a faster nail growth rate. A reviewed one man’s rate of nail growth over the course of 35 years.

At age 23, Dr. William Bean observed that his left thumbnail grew at a rate of 0.123 mm per day. By the time he reached age 67, this rate had dropped to 0.095 mm per day.

This change in speed may be because blood circulation slows with age.

Hormones

Your hormones can also affect the this rate. Take pregnancy, for example.

During this time, women a sudden and dramatic increase in estrogen and progesterone. These hormonal changes to result in rapid nail growth during pregnancy, but the rate of nail growth during lactation.

Outside of pregnancy, puberty is usually the most tumultuous time for your hormone levels. Nail growth is said to peak during puberty and decline as your hormone levels balance out with age.

Overall health

Chronic conditions can also on your nail growth, as well as the shape and overall appearance of your nails.

Nail symptoms are common with:

Some conditions may also affect your ability to recover from common nail disorders, such as an ingrown toenail.

If you have diabetes or other circulatory issues, make sure you monitor your nails closely. Make an appointment with your doctor if you experience a nail injury or notice anything unusual.

Biting and clipping

Onychophagia, or the chronic habit of biting your nails, has actually been with a faster growth rate. This because biting causes trauma to the nail, stimulating circulation in the nail bed.

This also supports the theory that frequent nail clipping makes your nails grow a little faster. Regular clipping doesn’t carry the same risks as nail biting, so if you want longer nails, clipping is the better route.

Your toenails grow much slower than your fingernails. They grow at an of 1.62 mm per month.

And if you lose a toenail, it can take for it to completely grow back. That’s as long as it would take your fingernail to regrow.

This is because your toenails are generally subjected to less trauma than your fingernails. Although you may stub your toe here and there, this temporary burst of circulation won’t have a lasting impact.

Although there aren’t any scientifically proven methods to make nails grow faster, there are a number of ways to increase the overall health of your nails.

The following methods will help strengthen your nails and prevent them from breaking, allowing them to remain long as you grow them out:

  • Take biotin. Researchers in one found that taking 2.5 milligrams of biotin every day reduced breakage and increased overall nail health.
  • Use nail hardeners (but sparingly). Nail hardeners may also strengthen the nail and reduce breakage. However, say to avoid prolonged use, as they can actually break down the nail over time. You should limit or avoid strengtheners that contain formaldehyde or formalin.
  • Avoid glue-on nails and toxic polishes. Frequently applying glue-on nails or toxic polishes your risk of breakage. Opt for nontoxic or water-based polishes whenever possible.
  • Groom your nails. Keeping your nails clean is key to overall nail health. Use a clean pair of clippers to trim them regularly. Once a week should be enough. Keep your cuticles pushed back or trimmed, too. And don’t forget to moisturize!

From the time of year to how old you are, there are a number of factors that affect how fast your nails grow. Although most of these factors are outside of your control, you can help the process along by practicing good nail hygiene.

If you feel like your nails are growing unusually slow — or are experiencing discoloration or other symptoms — talk to your doctor. Your symptoms may be tied to nutritional deficiencies or another underlying condition. Your doctor can help determine why this is happening and advise you on any next steps.