How much blood does the average person have?

An average adult has roughly 4.5 to 5.5 litres of blood, which is about 7 to 8 percent of body weight. A larger, taller person has more, and a smaller person less. A 175cm, 80kg man works out at about 5.15 litres using Nadler's formula, or roughly 64 mL for every kilogram of body weight.

What is Nadler's formula?

Nadler's formula estimates total blood volume from height and weight, with separate equations for men and women. For men it is 0.3669 times height in metres cubed, plus 0.03219 times weight in kg, plus 0.6041. For women it is 0.3561 times height cubed, plus 0.03308 times weight, plus 0.1833, giving litres.

How accurate is a blood volume estimate?

It is a population estimate, so an individual can sit above or below it depending on body composition, fitness and health. Nadler's formula is widely used as a practical guide, but it is not a measurement. This tool is for general information only and is not medical advice.

Blood Volume Calculator

This blood volume calculator estimates how much blood is in your body from your height, weight and sex, using Nadler's formula, the equation most widely used for the job. Blood volume rises with body size, so a tall, heavier person carries several litres more than a small one, and men tend to have a little more than women at the same height and weight. Enter your height in centimetres and your weight in kilograms, pick male or female, and you get your total blood volume in litres, the same figure in millilitres, and how many millilitres that works out to per kilogram of body weight. For most healthy adults blood makes up around 7 to 8 percent of body weight, or roughly 4.5 to 5.5 litres, and this tool puts a number on that for your own measurements. It is handy for biology and health study, for general curiosity, and for putting donation amounts into context, since a standard whole blood donation of around 470 mL is only a small share of the total. The result is a population estimate rather than a measurement, so treat it as a guide. It is general information only and not medical advice.

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Sex

Height (cm)

Weight (kg)

5.15 L

estimated total blood volume

In millilitres5,146 mL

Per kilogram64.3 mL/kg

SexMale

A 80 kg male who is 175 cm tall has an estimated blood volume of about 5.15 litres, roughly 64.3 mL per kg of body weight.

Nadler's formula gives a population estimate; your actual volume varies with body composition and health. General information only, not medical advice.

How it works

The calculator uses Nadler's formula, which links total blood volume to height and weight with a separate equation for each sex. Height is converted to metres and cubed, which captures overall body frame, then combined with weight to give a volume in litres. Men and women use slightly different constants because body composition differs on average. Dividing the volume by weight gives millilitres per kilogram, a figure that lands near the well known guide of about 70 mL per kilogram for adults and lets you compare bodies of different sizes on the same scale.

Worked example

Take a man who is 175 cm tall and weighs 80 kg. His height in metres is 1.75, and cubed that is 5.359. The male formula gives 0.3669 x 5.359 + 0.03219 x 80 + 0.6041, which is about 1.966 + 2.575 + 0.604, or 5.15 litres. That is 5,146 millilitres in total, and dividing by his 80 kg gives about 64.3 mL per kilogram. A woman of the same height and weight would come out a little lower because the female constants are smaller.

Related calculators

BMI Calculator: body mass index from height and weight.
Lean Body Mass Calculator: estimate lean mass.
Body Fat Calculator: estimate body fat percentage.
Blood Donor Calculator: next eligible donation date.

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