Medical calculator

AST to Platelet Ratio Index (APRI)

Calculates APRI from AST, the AST upper reference limit, and platelet count.

Enter AST, the laboratory upper limit of normal AST, and platelet count in 10^9/L.

APRI inputs

Use AST and platelet values from the same laboratory context whenever possible.

AST level

Aspartate aminotransferase value reported by the laboratory.

IU/L

Upper limit of normal AST

The source page uses 40 IU/L as a common default, but this should follow the local laboratory reference range.

IU/L

Platelet count

Enter platelet count in 10^9/L.

10^9/L