Blood Volume Estimator
Estimate total blood volume using Nadler's formula based on sex, height, and weight.
Use the Blood Volume Estimator
Patient Parameters
Enter patient parameters and click Calculate.
Estimated Blood Volume
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
The Blood Volume Estimator uses Nadler's formula — the clinical standard in transfusion medicine — to calculate a patient's total blood volume from sex, height, and weight. Results are displayed in liters and as mL per kg of body weight, which is the form most commonly used in perioperative and critical-care contexts. All computation runs locally in your browser; no data is sent anywhere.
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 adult pre-operative and transfusion assessments.