Work out effect size (cohen d) instantly with clear inputs, formula shown and shareable results.
Cohen's d expresses the difference between two means in standard deviation units, making it comparable across studies and independent of sample size. Cohen suggested 0.2, 0.5 and 0.8 as small, medium and large.
Cohen's d
d = (x̄₁ − x̄₂) / s_pooled, s_pooled = √((s₁² + s₂²)/2)
The pooled SD is 8.8204, so d ≈ 0.7256 — a medium to large effect.
A p value depends heavily on sample size; d measures the practical size of the difference regardless of n.