How Fast Does Hair Actually Grow?

Scalp hair grows at an average rate of about 0.35 mm per day, which works out to roughly 1 cm (0.4 inch) per month, or 15 cm (6 inches) per year. Individual rates range from 0.6 to 3.36 cm per month, varying with body region, sex, age and ethnicity.

Scalp hair grows at an average rate of 0.4 inch (1 cm) per month.

1. Scalp hair growth – 0.014 inches/day (0.36 mm/day)
2. Eyelash/brow growth – 0.006 inches/day (0.16 mm/day)
3. Beard hair growth – 0.015 inches/day (0.38 mm/day)

A hair length of 12 cm represents a hair growth of about 3½ to 20 months. Also, hair growth varies depending on body region. In addition to that, growth rate of hair is affected by gender, age, hair color and ethnicity too.

Do you remember that time when you went to a new salon and asked for a simple haircut, but ended up looking like you’d stuck a finger in an electrical socket?

Getting a bad haircut can be traumatic, to say the least, particularly when you need to wait for your hair to grow back. You wake up every morning, hoping against hope that your hair has miraculously fixed itself, but it seems like months before you can properly fix it.

This universal and embarrassing problem begs an important question: How fast does it normally grow? And is there any way to speed up the process?

Watching Water Boil Vs. Watching Hair Grow

As they say, “a watched pot never boils”, and the same thing is true of human hair. On average, scalp hair grows at a rate of about a third of a millimeter per day (roughly 0.35 mm). Don’t get too excited, as that only equals about 1 cm (0.4 inch) per month, or 15 cm (6 inches) over a whole year. Therefore, people waiting for their hair to grow back after a particularly terrible trim need to have some patience. It will take at least a season to bring back those beautiful locks that got chopped off.

Perception is a big factor in the appearance of hair, because if you have a very short haircut, the change in appearance will be much more dramatic. A crewcut will seem to grow very rapidly, doubling in length in a week or less, whereas a woman with hair to the middle of her back will not notice the change in length, despite the relatively even growth rates.

This slow growth of hair is particularly annoying for people who are already beginning to lose their hair and want to have a bit more hair to “work with”. This has led many people to seek ways to boost or speed up hair growth, but is it really possible?

The Secret To Fast-Growing Hair

That title is a bit of a tease, because there is no real secret, and there is no proven trick that makes hair grow dramatically faster. Your speed of growth is set mostly by your genes, your age, and the length of your follicles’ active (anagen) growth phase, none of which a shampoo or a smoothie can rewrite. What you can do is make sure nothing in your diet or lifestyle is dragging that natural rate down.

First of all, it helps to understand what hair actually is. A strand of hair is roughly 65-95% protein, mostly a tough fiber called keratin, with the rest made up of water, lipids, and trace minerals. Keratin is packed with the sulfur-containing amino acid cysteine, which is why your hair smells so bad when you singe one of your locks with a match by accident! Because hair is built from protein, a genuinely protein-poor diet can leave it weak and brittle, so balanced meals with protein sources like fish, eggs, and legumes, plenty of vegetables, and enough water to stay hydrated give your follicles the raw materials they need. Just keep your expectations realistic: feeding a healthy, well-nourished body more of these foods will not push growth past its genetic ceiling. The diet angle matters most when you are correcting a real shortfall, such as low iron or protein, rather than topping up someone who already eats well. There is even some evidence that a steady stream of sugary drinks is associated with a higher risk of hair loss, so easing off them certainly will not hurt.

Blood flow to the scalp is often suggested as a way to support healthy hair, since the follicles depend on blood to deliver oxygen and nutrients. The evidence here is thin rather than “surefire”, but it isn’t nothing: a small 2016 study found that several minutes of daily scalp massage modestly increased hair thickness in healthy men. Regular exercise and a relaxing head massage are good for you regardless, and they certainly won’t slow your hair down, so think of them as supporting a healthy scalp rather than as a guaranteed growth accelerator.

Turn Things On Their Head

The “inversion method”, as the name somewhat suggests, involves spending a few minutes a day with your head upside down, often paired with a scalp massage and a little oil. The idea is that hanging your head below your heart floods the scalp with blood, and that the extra blood flow delivers nutrients to the follicles and jump-starts faster growth. It is a popular internet trend, and people swear by their before-and-after photos.

Here is the catch, though: there is no scientific evidence that the inversion method actually speeds up hair growth or regrows lost hair, and it does nothing for male pattern baldness, which is driven by genetics and hormones rather than blood supply. Any benefit people notice most likely comes from the scalp massage and oils they use alongside it, not from being upside down. It is also worth a word of caution: hanging your head down raises blood pressure and can cause dizziness, so it is not a good idea if you are pregnant or have heart or blood-pressure problems.

What Should I Avoid For Speedy Hair Growth?

Aside from things you can do to improve hair growth, there are also certain things to avoid. Namely, putting tons of harsh chemicals in your hair, whether for styling or changing its color. These harsh chemicals can damage your follicles or “fry” the hair shaft, leaving it to snap off. That breakage won’t change how fast hair grows from the root, but it does stop you from keeping the length you grow.

You should also be aware of how often you blow-dry or straighten your hair, as this type of intense heat can increase hair breakage and loss. Using old brushes or combs, or those that are rough on the scalp, can also increase hair loss and damage follicle beds, resulting in slower hair growth. Every head of hair is different, and you should make sure that you understand the right tools, brushes, products, and styling techniques for your individual head! In other words, never be like this guy…

None of these habits will give you a full head of hair overnight, and nothing will push your hair past its natural pace. But by feeding your body well, going easy on the heat and harsh chemicals, and being gentle with your scalp, you give every one of those daily fractions of a millimeter the best chance to add up, so your hair can grow out to its full potential over the months and years.