Blood Volume Calculator - Estimate Total Blood Volume (Nadler and Lemmens)
Blood Volume Calculator
Estimated total blood volume from height and weight
Two Methods
Nadler’s equation is the most widely used. The Lemmens-Bernstein-Brodsky formula adjusts for body mass index and is shown for comparison.
Metric or Imperial
Enter height and weight in centimetres and kilograms, or inches and pounds.
Used in Medicine
Estimated blood volume appears in transfusion planning, anaesthesia and physiology teaching.
Private
Nothing you enter is stored or sent.
What Blood Volume Is
An adult’s total blood volume is roughly 4 to 6 litres, about 7 percent of body weight. It depends mostly on body size and sex: a larger person has more blood, and for the same size men carry a little more than women. Doctors estimate it with formulas because measuring it directly needs specialised tests.
Nadler’s equation, published in 1962, was fitted to measurements in healthy adults and uses height cubed and weight. The Lemmens-Bernstein-Brodsky formula, from 2006, accounts for the fact that fat tissue holds less blood per kilogram than lean tissue, so it gives a smaller volume than a simple per-kilogram figure for people with a high body mass index. Both are estimates for typical adults and can be off in pregnancy, in children and in some medical conditions.
Key Takeaways
- Estimates only: The formulas describe average healthy adults, not you in particular.
- Not for children: Neither equation is meant for children or for pregnancy.
- Related calculators: See also the Body Surface Area Calculator and the Creatinine Clearance Calculator.