Blood Volume Estimator
Estimate total blood volume using Nadler's formula based on sex, height, and weight.
Patient Parameters
Enter patient parameters and click Calculate.
Estimated Blood Volume
—
L
— mL
mL per kg
—
Normal: 65–80 mL/kg
Red Cell Mass
—
At entered hematocrit
Maximum Allowable Blood Loss (MABL)
Hct ≥ 30%
—
mL
Hct ≥ 25%
—
mL
Hct ≥ 21%
—
mL
MABL = EBV × (Hctstart − Hctmin) / Hctstart. Requires current hematocrit input.
Nadler's Formula Applied
Reference: Nadler SB, Hidalgo JU, Bloch T. Surgery 1962;51(2):224–232.
Summary
Estimate total blood volume using Nadler's formula based on sex, height, and weight.
How it works
- Select the patient's biological sex (male or female).
- Enter height in centimeters or feet/inches.
- Enter body weight in kilograms or pounds.
- The estimator applies Nadler's coefficients to compute total blood volume.
- Results appear instantly in liters and mL/kg alongside a breakdown of the formula.
Use cases
- Estimate allowable blood loss before triggering a transfusion threshold.
- Support pre-operative planning and fluid management decisions.
- Calculate maximum allowable blood loss (MABL) at a target hematocrit.
- Verify dosing calculations for medications given per unit blood volume.
- Educate medical students on Nadler's formula in a clinical-skills context.
- Cross-check reference values for pediatric and adult patients.
Frequently Asked Questions
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Last updated: 2026-05-23 ·
Reviewed by Nham Vu