Estimated Blood Volume Calculator
Estimate blood volume from weight and a selected reference coefficient.
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Estimated blood volume
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Weight-based estimate; not a measured circulating volume
Estimated blood volume
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Coefficient used: — mL/kg
About
Estimated blood volume is body weight multiplied by a selected reference coefficient. Coefficients differ by age, sex/reference group, body composition, and source, so this page exposes the coefficient instead of treating one value as universal. The result is an estimate, not a direct measurement.
Formula
Interpretation
Reference coefficients: Common teaching estimates include adult male 75 mL/kg, adult female 65 mL/kg, child 70–75 mL/kg, infant 80 mL/kg, and neonate 85–100 mL/kg. Local references may differ.
Worked example: A 70 kg adult using 75 mL/kg gives an estimated blood volume of 5,250 mL, or 5.25 L.
Limitations: Weight-based coefficients do not measure an individual's circulating volume and may be less representative at extremes of body composition or illness. This estimate does not calculate transfusion, blood loss replacement, or fluid treatment.
FAQ
Disclaimer
Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.