Effect Size Calculator

Effect size measures the practical significance of a result independent of sample size. A statistically significant result can have a trivially small effect size — effect size tells you whether it matters

The calculator uses the standard published formula for effect size. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches. You can enter values in the units shown — the calculator handles all conversions internally.

The calculator applies the standard formula for this type of calculation. See the 'How It Works' steps above for the detailed formula breakdown.