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Estimated Blood Volume Calculator (Nadler and mL/kg)
Estimated blood volume (EBV) for an adult is calculated with Nadler's equations from height, weight and sex. For a man: EBV in liters = 0.3669 × height³ (m) + 0.03219 × weight (kg) + 0.6041. A man who is 180 cm and 80 kg has an EBV of about 5.3 L. A quicker method multiplies weight by a published mL/kg figure for the patient group. This calculator does both.
Prepared by Prospyr · Reviewed October 3, 2026 · Free, no sign-up, runs in your browser
Estimated blood volume (Nadler)
4,189mL
4.19 L, or 62 mL/kg for this patient.
| Method | mL |
|---|---|
| Nadler | 4,189 |
| Adult 65–70 mL/kg | 4,423–4,763 |
Decision support only; it does not replace clinical judgment. Blood volume estimates are population averages and vary with body composition, so use them as an arithmetic aid and follow your protocol.
Estimated blood volume formula: Nadler's equations
Nadler and colleagues (1962) fitted blood volume to height cubed and weight in normal adults. Height H is in meters, weight W in kilograms, result in liters.
| Sex | EBV (L) |
|---|---|
| Male | 0.3669 × H³ + 0.03219 × W + 0.6041 |
| Female | 0.3561 × H³ + 0.03308 × W + 0.1833 |
Worked example, man: 180 cm, 80 kg. H³ = 1.8³ = 5.832. EBV = 0.3669 × 5.832 + 0.03219 × 80 + 0.6041 = 2.140 + 2.575 + 0.604 = 5.319 L (5,319 mL).
Worked example, woman: 165 cm, 60 kg. H³ = 1.65³ = 4.492. EBV = 0.3561 × 4.492 + 0.03308 × 60 + 0.1833 = 1.600 + 1.985 + 0.183 = 3.768 L.
Blood volume per kg: mL/kg by patient group
The weight-based method is EBV = weight × mL/kg. One published table of blood volume in children lists these ranges.
| Group | mL/kg | Example |
|---|---|---|
| Neonate | 85–90 | 3 kg: 255–270 mL |
| Infant | 75–80 | 10 kg: 750–800 mL |
| Child | 70–75 | 20 kg: 1,400–1,500 mL |
| Adult | 65–70 | 70 kg: 4,550–4,900 mL |
The tool shows the range and uses the midpoint as the headline number. Other references publish other figures, for example separate values for adult men and women, so check the reference your protocol names.
Blood volume calculator: how to use it with the allowable blood loss tool
Pick a method, enter height and weight, and read the result. The comparison table appears when both methods can be calculated. Your inputs stay in the address bar so you can share them.
The next step many teams document is the allowable blood loss, which starts from an EBV. Take the figure from here into the allowable blood loss calculator. It is decision support only.
For aesthetic and plastic surgery practices
Practices that do larger-volume procedures keep a pre-operative record with weight, hematocrit and an estimated blood volume. This gives you the EBV with the method written down. Prospyr's plastic surgery software keeps that record with the chart and schedule.
Frequently asked questions
How do you calculate estimated blood volume?
For adults, use Nadler's equation: men 0.3669 × H³ + 0.03219 × W + 0.6041 liters, women 0.3561 × H³ + 0.03308 × W + 0.1833 liters, with height in meters and weight in kg. For a quicker estimate, multiply weight by a mL/kg figure for the age group. Both are available in the tool above.
What is the Nadler formula for blood volume?
The Nadler formula comes from a 1962 paper in Surgery titled Prediction of blood volume in normal human adults. It predicts blood volume from height cubed and weight, with separate constants for men and women. A 165 cm, 60 kg woman comes to 0.3561 × 1.645 + 0.03308 × 60 + 0.1833 = 3.77 L.
How many mL/kg is the blood volume of an adult?
One published table lists neonates at 85 to 90 mL/kg, infants 75 to 80, children 70 to 75 and adults 65 to 70 mL/kg. A 70 kg adult is therefore about 4,550 to 4,900 mL by this method. Different references give slightly different values, so name the one you use.
Why does the mL/kg result differ from Nadler?
Nadler uses height and sex as well as weight, so it reflects body size beyond weight alone. A fixed mL/kg figure treats every patient in the group the same. For the 180 cm, 80 kg man above, Nadler gives 5,319 mL (66.5 mL/kg), within the adult 65 to 70 mL/kg range.
Is estimated blood volume the same as circulating blood volume?
In this context, yes. The numbers are estimates of total circulating blood volume from body size, not measurements. Actual volume varies with body composition, hydration and health, so any use should treat it as an approximation.
Is Nadler valid for children and very small adults?
Nadler's paper describes normal adults, so use the mL/kg method by age group for children. The calculator warns when height is under about 140 cm or weight under 35 kg.
What do practices use estimated blood volume for?
EBV is the input for the allowable blood loss formula and for relating measured blood loss to total volume. This page only produces the EBV figure; it does not suggest thresholds or any transfusion decision.
Sources and scope
- Nadler SB, Hidalgo JH, Bloch T. Prediction of blood volume in normal human adults. Surgery. 1962;51(2):224-232. PMID 21936146
Original paper for the height-and-weight equations. The male and female coefficients used here are the standard published ones.
- Pediatric perioperative fluid management. Saudi J Anaesth. 2021 (PMC8477784), Table 4, "On blood volume in children"
Peer-reviewed source for the mL/kg ranges: neonates 85-90, infants 75-80, children 70-75, adults 65-70.
Decision support only; it does not replace clinical judgment. Blood volume figures are population estimates. Confirm against your protocol; decisions belong to the treating provider.