Shannon Diversity Index Calculator

From Species Counts

Enter individual counts for up to 8 species to compute diversity

Species 1 count

Species 2 count

Species 3 count

Species 4 count (0 if none)

Species 5 count (0 if none)

Species 6 count (0 if none)

Species 7 count (0 if none)

Species 8 count (0 if none)

Formula

H' = −Σ(pᵢ × ln(pᵢ)), where pᵢ = nᵢ/N. Hmax = ln(S). Evenness J = H'/Hmax. Simpson's D = Σ(nᵢ(nᵢ−1)) / (N(N−1)).

Frequently Asked Questions

What is the Shannon diversity index?

The Shannon diversity index (H') quantifies the uncertainty in predicting the species of a randomly chosen individual. Higher values indicate greater diversity. H' = −Σ(pᵢ × ln(pᵢ)), where pᵢ is the proportion of species i.

What is evenness?

Evenness (J) measures how equally individuals are distributed among species: J = H'/Hmax, where Hmax = ln(S). J = 1 means all species are equally abundant; J near 0 means one species dominates.

How does Shannon index differ from Simpson's index?

Shannon index is more sensitive to rare species, while Simpson's index gives more weight to abundant species. Both measure diversity but from different perspectives.

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