ABL / EBV

Allowable Blood Loss using Gross's formula: ABL = EBV × (Hᵢ − H_f) ÷ Hᵢ

Weight (kg)

Patient category

Initial Hct (%)

Acceptable final Hct (%)

Result

1,875 mL

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EBV = 70 kg × 75 mL/kg = 5250 mL
ABL = EBV × (Hi − Hf) ÷ Hi
ABL = 5250 × (42 − 27) ÷ 42
ABL = 1875 mL

Clinical note: ABL estimates the volume of blood loss tolerated before transfusion becomes appropriate. Use alongside hemodynamics, ongoing-loss rate, and patient-specific transfusion triggers. Education only — not a substitute for clinical judgment.