Blood Volume Calculator — Nadler Equation
Calculate your estimated total blood volume using the clinically validated Nadler equation. Enter your sex, weight and height to get a personalised blood volume estimate in litres and mL/kg — useful context before surgery, blood donation or studying physiology.
Sex
kg
cm
Nadler's equation estimate — individual variation of ±10% is normal
- 1
Height in metres
175 ÷ 100 = 1.75 - 2
Height cubed (H³)
1.75³ = 5.35938 - 3
Blood volume (Nadler)
0.3669 × 5.35938 + 0.03219 × 70 + 0.6041 = 4.82
How does this calculator work?
Nadler's equation (1962) estimates total blood volume from height and weight: for males BV = 0.3669×H³ + 0.03219×W + 0.6041, and for females BV = 0.3561×H³ + 0.03308×W + 0.1833 (H in metres, W in kg, result in litres). Typical adult values are 4–6 L, or roughly 65–80 mL/kg.
Formula
How this is calculated
Blood volume cannot be measured directly without specialised nuclear medicine techniques, so clinicians use regression equations derived from large populations. The most widely cited is Nadler's equation (1962), which uses height cubed and body weight as predictors — height cubed approximates lean body volume, and weight captures body mass including fat. Separate coefficients for males and females reflect average differences in haematocrit (the proportion of red cells) and body composition.
For a 70 kg male of 175 cm, the equation gives roughly 5.0 L, consistent with the commonly quoted "5 litres" figure. Taller or heavier individuals have larger blood volumes, and males average slightly more than females at the same height and weight. Blood volume scales roughly 65–80 mL per kg of body weight in healthy adults.
This is an estimate with around ±10% individual variability. Clinical measurement (using labelled albumin or chromium-tagged red cells) is far more precise but impractical outside hospital settings. Use this result for educational and general planning purposes only — medical decisions such as transfusion volumes require direct clinical assessment.
Frequently asked questions
Nadler's equation is validated on large populations and accurate to within about ±10% for most healthy adults. It can be less accurate at extremes of body weight (severe obesity or cachexia) and does not account for fitness level, altitude adaptation, or disease states.
Healthy adults can typically tolerate losing up to about 15% of blood volume (class I haemorrhage) without significant symptoms. Loss of 30–40% causes serious haemodynamic compromise and requires urgent intervention. Blood banks take approximately 450–500 mL (8–10%) per donation, which the body replaces within weeks.
Yes. Blood volume increases during pregnancy (up to ~45%), decreases with dehydration, increases with altitude acclimatisation and endurance training, and declines gradually with age. The calculator estimates volume at your current weight and height only.
TG we-Calculate Editorial Team. (2026). Blood Volume Calculator — Nadler Equation [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/blood-volume-calculator
TG we-Calculate Editorial Team. "Blood Volume Calculator — Nadler Equation." TG we-Calculate. 2026. https://we-calculate.com/calculator/blood-volume-calculator.
TG we-Calculate Editorial Team, "Blood Volume Calculator — Nadler Equation," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/blood-volume-calculator
@misc{wecalculate_blood_volume_calculator, title = {Blood Volume Calculator — Nadler Equation}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/blood-volume-calculator}}, year = {2026}, note = {TG we-Calculate} }
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