Work out allowable blood loss instantly with clear inputs, formula shown and shareable results.
Calculates how much blood can be lost before the haematocrit falls to the chosen transfusion trigger, using estimated blood volume.
Allowable blood loss
ABL = EBV x (starting Hct - minimum acceptable Hct) / starting Hct, with EBV = weight x mL/kg
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
Restrictive thresholds around a haemoglobin of 70 to 80 g/L are standard in stable patients; cardiac disease may warrant higher.
Yes. Dilution lowers haematocrit without further red cell loss, so the calculation assumes normovolaemia.