How Much Blood Is in the Human Body?

If you've ever wondered how many pints of blood are in the human body and how much is taken during each donation, know that you aren't alone. So let's get into it!

Ever wondered just how much blood is coursing through your veins? Whether you're a regular blood donor or considering donating for the first time, you may have wondered just how much blood you have to give.

If so, you're not alone! All of us at Our Blood Institute want to ensure you feel safe and prepared for your next donation, so we're here to answer a few questions our phlebotomists regularly receive.

Questions like:

How Many Pints of Blood Are in the Human Body?

The amount of blood in the human body does, of course, depend on the human! A person's age, sex, body size and overall health all factor into their overall blood volume. On average, though, the adult human body contains around 10.5 pints of blood. Put another way, that's about five liters or 1.3 gallons.

To put those numbers into context, that's somewhere around 8-10% of the average adult's body weight.

Men vs. Women

Typically, men have slightly more blood than women due to their generally larger body size and muscle mass. Notably, pregnant women tend to be an outlier, with a blood volume increase of roughly 50%!

Newborn Babies

The average newborn only has about a quarter of a liter of blood, amounting to roughly half a pint.

Children (6-12)

Similar to adults, children in this age group have around 70 mLs of blood per kilogram. That means that a 66-pound child would have around 2 liters of blood circulating in their body.

What Is Blood Made Of?

Blood is a complex mixture of cells and fluids, each playing a vital role in keeping you healthy. Here's what makes up your blood:

Red blood cells (RBCs)

These carry oxygen from your lungs to the rest of your body and return carbon dioxide to be exhaled.

White Blood Cells (WBCs)

The defenders of your body, these cells fight infections and protect against foreign invaders.

Platelets

These tiny cells are crucial for blood clotting and wound healing. Roughly 2 million units of platelets are transfused each year in the United States, often going to cancer patients, transplant recipients and trauma victims.

Platelets have a short shelf life and must be used within five days of donation, so if you'd like to learn more about platelet donation or are considering becoming a donor, we encourage you to check out our page on all things platelets. Your community will thank you!

Platelet Donation Info

Plasma

The yellowish liquid that makes up about 55% of your blood’s volume. It’s mostly water but also contains proteins, hormones, and waste products.

Plasma donation is often the ideal choice for donors with AB blood types and can be give every 28 days.

Become a Plasma Donor

How Much Blood Is Taken When You Donate?

About one pint of blood is taken when donating whole blood. That's only about 10% of your blood overall and is perfectly safe. Also don't worry, your body actually works quite quickly to replace it!

Following your donation, your body will have replaced your lost plasma in roughly 24 hours. Red blood cells, though, take a little longer, about 4 to 6 weeks. That's why we require at least 56 days between whole blood donations.

How Much Do You Have to Weigh to Donate Blood?

You may also be wondering about potential weight requirements for eligible donors. A fair question! Under FDA guidelines:

Donors over the age of 17 must be at least 110 pounds.
Sixteen-year-olds can give blood if over 125 pounds with permission from a parent or guardian
Seventeen-year-olds can give blood if over 125 pounds but do not need permission from a guardian or parent

Still don't know if you're able to donate blood? Check out our FAQ page designed to answer all your eligibility-related questions.

Ready to Donate?

Now that you know how much blood is in the human body — around 10.5 pints — and how much blood is taken when you donate — a perfectly safe 10% — we hope you consider giving when you can!

Each time you give blood, you're potentially saving up to three lives. Hospitals and emergency services rely on blood donations for surgeries, cancer treatments, chronic illnesses, and traumatic injuries. Your single pint can make a huge difference in someone’s life.

Schedule Your Donation