Transferrin Saturation Calculator

About this calculator

Transferrin saturation is calculated as TSAT = (serum iron / total iron-binding capacity) × 100, expressing what fraction of the blood's iron-carrying protein, transferrin, is actually loaded with iron rather than running empty. TIBC indirectly measures how much transferrin is circulating, so the ratio reflects iron availability independent of how much transferrin the liver happens to be producing.

Hematologists and primary care physicians order this alongside serum ferritin as part of an iron studies panel, since a low TSAT points toward iron deficiency while a persistently elevated TSAT — typically above 45% — is one of the earliest markers used to screen for hereditary hemochromatosis, an iron-overload disorder. Because acute inflammation and liver disease also shift TIBC, clinicians interpret the ratio alongside ferritin and clinical context rather than in isolation.