How Many Pints of Blood Are in the Human Body?
about 10 pt
An adult who weighs 150 to 180 pounds has about 10 pints of blood, or 1.2 to 1.5 gallons, according to the American Red Cross.
In liters: 5 to 6 liters for a healthy adult, according to the NIH. NHS Blood and Transplant in the UK also says around 10 pints.
Adult blood volume by source
| Source | As published | Liters | US pints |
|---|---|---|---|
| American Red Cross | 1.2–1.5 gal, or 10 pints, for an adult of 150–180 lb | 4.5–5.7 | 9.6–12 |
| NIH (NHLBI and MedlinePlus) | 5–6 liters | 5–6 | 10.6–12.7 |
| NHS Blood and Transplant | About 5 liters; also around 10 pints | 5 | 10.6 |
Why do sources give different amounts?
The amount of blood depends on the size of the body. The American Red Cross says a bigger body holds more blood, and it gives its figure of about 10 pints for an adult who weighs 150 to 180 pounds.
The sources also describe blood as a share of body weight in different ways. The Red Cross says blood is about 10% of an adult's weight, while NHS Blood and Transplant (NHSBT) says roughly 8%.
Each source gives a rounded figure in its own units, but the figures land close together once they are converted, as the table shows. Every one of them includes about five liters (litres).
Are these US pints or UK pints?
A US pint is 473 ml, while a UK (imperial) pint is 568 ml. So ten UK pints hold more blood than ten US pints.
The Red Cross is a US source, and its numbers line up in US units: 1.2 to 1.5 gallons is 9.6 to 12 US pints, a range that fits its pint figure. It also counts one unit of donated whole blood as 1 pint.
NHSBT, a UK service, also says the average adult has around 10 pints, but that page does not say which pint it means. Ten UK pints would be about 5.7 liters and ten US pints about 4.7 liters; NHSBT's other figure, about 5 liters, falls between the two. To convert other amounts, use the pints to liters converter.
How much blood is taken in one donation?
In the US, a whole blood donation collects about 1 pint, plus several small test tubes for lab tests, according to the Red Cross.
In the UK, a scale stops the donation at 470 ml, which NHSBT calls just under a pint. That is 0.99 of a US pint, so the two donations are almost the same size. Your blood service can answer questions about your own donation.
Blood in the human body: questions
How many liters of blood are in the human body?
Healthy adults have about 5 to 6 liters, according to the US National Institutes of Health in both an NHLBI handout and MedlinePlus. NHSBT says about 5 liters, and the Red Cross range works out to 4.5 to 5.7 liters.
How many gallons of blood are in the human body?
The Red Cross says an adult has 1.2 to 1.5 gallons of blood. The NIH range of 5 to 6 liters works out to about 1.3 to 1.6 gallons, so the two sources are close.
How much blood does a newborn baby have?
The American Red Cross says a newborn baby's body holds only around a cup of blood. Because the amount of blood grows with body size, the adult figures on this page do not apply to children.
How long does it take the body to replace donated blood?
The Red Cross says the plasma from a donation is replaced within about 24 hours, while red cells take about four to six weeks. For that reason, it requires at least eight weeks between whole blood donations. In the UK, NHSBT asks men to wait at least 12 weeks and women 16 weeks.
Related
Sources
- American Red Cross, Whole Blood Components, checked
- American Red Cross, What Happens to Donated Blood?, checked
- American Red Cross, Questions About Donating Blood, checked
- NHS Blood and Transplant, How your body replaces blood, checked
- NHS Blood and Transplant, Blood group basics, checked
- NHS Blood and Transplant, The donation process, checked
- National Heart, Lung, and Blood Institute (NIH), Donate Blood. Save a Life. (2022 handout), checked
- MedlinePlus (National Library of Medicine, NIH), Cardiovascular system, checked
Sources: Unit definitions: NIST Handbook 44 · Last reviewed · Report an error
https://howmanyounces.com/how-many-pints-of-blood-in-the-human-body/