Estimated Blood Volume Calculator (Adult Nadler & Lemmens)

It is a formula-based reference value derived from body size and an explicitly selected model. It is not a direct measurement of the blood currently circulating in an individual.

Sources: [1, 2, 4]

Nadler estimates adult blood volume from height, weight, and one of its historical male or female coefficients. The formula was developed in normal adults and is not an automatic model for children, pregnancy, or major fluid shifts.

Sources: [1, 3]

Lemmens–Bernstein–Brodsky is an adult height-and-weight model that derives an indexed mL/kg estimate from BMI. It was proposed because a fixed 70 mL/kg assumption can overestimate blood volume in obesity.

Sources: [2, 3]

The applicable protocol, study, institution, or clinical workflow should name the model. This page does not select Nadler or Lemmens automatically from BMI, sex, age, or body size.

Sources: [1, 2]

Weight alone does not represent all body compartments proportionally. Lemmens adjusts the indexed mL/kg value as BMI rises, but it remains an adult formula estimate rather than a measurement.

Sources: [2, 3]

It multiplies the submitted weight by an mL/kg coefficient that the user obtained from a specific external protocol or standard. The calculator does not infer an age group, population, or correct coefficient.

Sources: [5, 6]

Not automatically. Pediatric, neonatal, and preterm estimates depend on age, gestation, clinical setting, and institutional protocol. Use a source that is specific to that population.

Sources: [5, 6]

Pregnancy changes blood volume substantially. These adult formulas and a generic coefficient should not be treated as a real-time pregnancy blood-volume measurement or a treatment basis.

Sources: [3, 4]

No. Active bleeding, dehydration, fluid administration, transfusion, edema, ascites, critical illness, and rapid fluid shifts can make a formula estimate differ materially from current circulating volume.

Sources: [3, 4]

No. Maximum allowable blood loss requires separate perioperative assumptions and hematologic targets. This page deliberately does not calculate it.

Sources: [5, 6]

No. It does not assess hemoglobin, ongoing loss, perfusion, hemodynamics, organ function, or a treatment protocol and gives no transfusion or fluid recommendation.

Sources: [6, 7]

Teaching tables summarize different populations, ages, sources, and protocols as ranges. A listed value is not a universal standard, which is why coefficient mode requires an explicitly selected external protocol value.

Sources: [5, 6]