ASTM D2270 Viscosity Index from Free Temperatures

Enter two kinematic viscosity measurements at any two temperatures. The module estimates viscosity at 40 °C and 100 °C using an ASTM D341-style relationship, then calculates Viscosity Index using ASTM D2270 equations.

Technical note: this calculator is supplied as a web implementation template. Validate against the current official ASTM D341 and ASTM D2270 standards before using for accredited reporting, certification, or specification decisions.