Compute species richness, Shannon–Wiener H′, and Pielou evenness from a list of counts.
| S (richness) | – |
| N (total) | – |
| H′ | – |
| Evenness | – |
Use this calculator when you have abundance counts for each species (or type) in a sample and want a standard diversity index.
Parse the counts as a comma-, semicolon-, or space-separated list of positive numbers. N is the sum, S is how many positive counts you entered. H′ = −Σ pᵢ ln pᵢ with pᵢ = countᵢ / N (natural log). Evenness is H′ / ln(S), or 1 when S is 1. Zeros and non-numbers are dropped.
This is sample diversity, not a rarefaction or a Chao estimator. Different sampling effort still changes H′.
Counts: Abundances, e.g. 10, 20, 5, 15.
S: Number of types with a positive count.
N: Total of the counts.
H′: Shannon–Wiener index (nats).
Evenness: Pielou J′ = H′ / ln(S).
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