Grain Size Calculator

Calculate ASTM grain size numbers and convert between different grain size measurements using ASTM E112 standard methods. Grain size significantly affects material properties including strength, toughness, and ductility.

Range: 0 to 14 (ASTM E112)

Magnification used for measurement (default: 100x)

About Grain Size Measurement

Grain size is a critical microstructural parameter that affects material properties. ASTM E112 provides standardized methods for determining average grain size:

  • ASTM Grain Size Number (G): Logarithmic scale where G = log₂(N) + 1, where N is grains per square inch at 100x
  • Intercept Method: Count grain boundary intercepts along test lines
  • Planimetric Method: Count grains within a known test area
  • Comparison Method: Compare microstructure to standard charts

Note: This calculator uses formulas from ASTM E112. For official grain size determination, follow the complete ASTM E112 standard procedures.

Need More Help?

Learn more about microstructural analysis and grain size measurement in our guides.

View Microstructural Analysis Guide →