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Free Blood Volume Calculator

Estimate total blood volume from height, weight, and sex using the standard Nadler equation.

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Estimates total blood volume using the standard Nadler equation (Nadler SB, Hidalgo JU, Bloch T. "Prediction of blood volume in normal human adults", Surgery 1962;51(2):224-232). This is a widely-published, standard reference estimation formula based on height, weight, and sex. For general reference and educational purposes only — not a medical diagnosis. Consult a doctor for actual clinical blood volume assessment.

How it works

Enter sex, height, and weight. The tool applies the sex-specific Nadler coefficients to estimate total blood volume in liters and milliliters.

  1. Enter sex.
  2. Enter height (cm).
  3. Enter weight (kg).
  4. Click Calculate to see your results.

Examples

Male, 180 cm, 70 kg

Estimated blood volume ≈ 5.0 L, using the Nadler equation for men.

Who should use it

  • Estimating blood volume for surgical/anesthesia reference calculations.
  • Physiology education.

Industry applications

  • Anesthesiology and surgical reference
  • Physiology education

Advantages

  • Long-established, widely-cited standard formula.
  • Feeds directly into related calculators (Allowable Blood Loss, Plasma Volume).

Limitations

  • An estimate only — not an actual measured blood volume.

Common mistakes to avoid

  • Entering height in the wrong unit (this tool expects centimeters).

Best practices

  • Use accurate, current height and weight measurements for the best estimate.

Tips

  • Use this estimate together with the Allowable Blood Loss Calculator to reference how much blood loss might be sustained before reaching a target hematocrit.

Frequently asked questions

Yes, with no signup and no limit on how many calculations you run.
It is a widely-cited, standard reference formula from 1962 still commonly used today, though it is an estimate — actual blood volume varies by individual health, hydration, and other factors.
It is commonly referenced in anesthesiology and surgery to estimate allowable blood loss, and in physiology education generally. See the related Allowable Blood Loss and Plasma Volume calculators.

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