Calculate Shannon and Simpson diversity indices from taxon abundances.
Shannon and Simpson answer different questions: Shannon responds strongly to the presence of rare taxa while Simpson responds to how dominant the most abundant taxon is. Evenness normalises Shannon by the maximum possible for that richness. Reporting one index alone can be misleading, because a community can be rich but heavily dominated, which the two indices characterise differently.
Microbiome Diversity
Shannon H = −Σ pᵢ ln pᵢ; Simpson D = 1 − Σ pᵢ²
Shannon H = −Σ pᵢ ln pᵢ; Simpson D = 1 − Σ pᵢ² Shannon and Simpson answer different questions: Shannon responds strongly to the presence of rare taxa while Simpson responds to how dominant the most abundant taxon is. Evenness normalises Shannon by the maximum possible for that richness.
Reporting one index alone can be misleading, because a community can be rich but heavily dominated, which the two indices characterise differently.
This calculator takes 5 inputs: Abundance of taxon 1, Abundance of taxon 2, Abundance of taxon 3, Abundance of taxon 4, Abundance of taxon 5. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.