Calculation of Estimated Total Blood Volume

Standard Calculation Methods

The traditional formula for calculating estimated blood volume is EBV = 70 mL/kg × body weight, which is the standard value used for adults of normal weight, as recommended by the British Journal of Anaesthesia 1, 2
The estimated blood volume for adults can be calculated using the formula EBV = 70 mL/kg × body weight, according to the British Journal of Anaesthesia 1, 2

For acute normovolemic hemodilution (ANH), a more precise formula is used: V = EBV × (Ho − Hf / Hav), where V = volume to be removed, EBV = estimated blood volume, Ho = initial hematocrit, Hf = desired hematocrit, and Hav = average hematocrit, as described by the British Journal of Anaesthesia 1
For pediatric patients, blood volume varies by weight, with estimated total blood volumes of approximately 50-99 mL for patients ≤1 kg, 100-200 mL for patients 1.1-2 kg, >200 mL for patients 2.1-12.7 kg, >800 mL for patients 12.8-36.3 kg, and >2200 mL for patients >36.3 kg, as reported by Clinical Infectious Diseases 3

For therapeutic phlebotomy, the standard volume removed is 500 mL per session in adults, as recommended by Praxis Medical Insights 2
In patients with cardiac disease, extra caution is needed during phlebotomy procedures, with normovolemia maintained by matching volume replacement with blood removal, as recommended by the British Journal of Anaesthesia and Praxis Medical Insights 1, 2
For pediatric blood sampling, recommended volumes are based on weight and total blood volume to avoid excessive blood draw, as reported by Clinical Infectious Diseases 3