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In 2004, Xie Qiuping set the world record for longest hair at 18 feet and 5.5 inches. You might think that the weight of all that hair would be stressful on her head and neck. But would it?

How much does hair actually weigh?

The short answer is “not very much.” Unless your hair is very long, it’s unlikely to weigh more than about a pound.

Keep reading to learn roughly how much your hair weighs. Just for fun, we’ll also estimate the weight of Xie Qiuping’s record-setting tresses.

It’s almost impossible to calculate the exact weight of your hair unless you plan on shaving your head. Even if two people have the same hair length, the weight will be different.

Individual factors such as your hair density, coarseness, and hydration are all going to influence the weight.

Weight of a single strand of hair

To estimate how much each strand of hair on your hair weighs, let’s look at the data from a 2018 study published in the Journal of Visualized Experiments. In the study, researchers cut small samples of 30 to 50 hairs from 21 African American participants.

The average weight of these samples was 0.00064 ounces per inch of hair.

It’s not clear exactly how many hairs were in each sample, but assuming every sample had between 30 and 50, we can estimate that the average weight of an inch-long piece of hair is somewhere between 0.000013 and 0.000021 ounces.

Using these estimates, a single 6-inch long piece of hair would weigh between 0.000076 to 0.00013 ounces.

Put another way, it would take about 7,900 to 13,000 hairs to make one ounce.

Weight per square inch of hair

In a 2017 study published in Scientific Reports, researchers estimated that a 5- to 10-milligram hair sample would be 75 square millimeters. Converted to imperial for a 1-inch-long hair, this is roughly 0.0037 to 0.0074 ounces per square inch.

So if your hair is 6 inches long, the weight of all the hair in that patch would be roughly 0.022 to 0.044 ounces.

Weight of all your hair

The average healthy person has between 80,000 to 120,000 hairs on their scalp.

If we use the weight of a single strand of hair that we calculated above, this gives us an estimated total weight somewhere between 6.1 and 13 ounces for somebody with 6-inch-long hair.

In reality, the actual weight of your hair will almost certainly be lower.

For most hairstyles, the length of your hair will be cut to varying lengths. Also, not every hair on your head is fully grown. Roughly 85 to 90 percent of your hairs are in the growth phase at any given time.

Xie Qiuping hair weight

How much would Xie Qiuping’s record hair weigh?

There’s no way to know for sure, but we can make a very rough estimate.

Let’s assume:

  1. She had a total of about 100,000 hairs on her head
  2. The average hair on her head was halfway grown out
  3. The weight of each hair on her head was halfway between our two estimates

Put all together, we get an estimate of about 11.7 pounds.

If you want to know exactly how much your hair weighs when it’s wet compared to dry, you can weigh yourself before and after you bathe.

However, the difference is likely going to be small and is likely going to be less than daily fluctuations due to your level of hydration, the amount of food you eat, and errors in your scale.

Most of the weight is going to come from water trapped between your hairs. The longer and wetter your hair, the more weight you’ll gain. Even if you have long hair, it’s unlikely that it would add more than a few ounces.

Despite the tiny size of an individual strand of hair, it can withstand about 3.5 ounces of force. Collectively, the 100,000 or so hairs on your head could theoretically withstand about 10 to 15 tons of force.

Your hair’s strength comes from long chains of the protein keratin. Keratin is the same protein that gives nails and claws their strength.

Hair can swell by about 15 percent by absorbing water. In theory, drying out your hair may decrease its weight. But unless you’re using a scale that can measure many decimal places, the difference is unlikely to be perceptible, and you’ll likely damage your hair.

If you really want to decrease the weight or volume of your hair, the easiest way would be to get a haircut.

Weighing yourself after you get out of the shower might add a small amount of weight to the scale, especially if your hair is very long and very wet.

If you want to get an extremely precise reading, you may want to avoid weighing yourself directly after bathing.

To weigh yourself accurately, you can try to follow these tips:

  • There’s no need to weigh yourself more than once per week. Day-to-day fluctuations are too high to give you an accurate idea of how your weight is changing.
  • Weigh yourself first thing in the morning before you eat or drink.
  • Wear the same clothes (or no clothes) each time you weigh yourself.
  • Decide if you will go to the bathroom before or after weighing yourself and try to stay consistent.

The hair on your head is unlikely to weigh more than about a pound unless it’s very long. Wet hair weighs more than dry hair, mostly because of water trapped between individual strands.

If you want to weigh yourself as accurately as possible, you may want to do it first thing in the morning with dry hair and before you eat or drink anything.