Shannon Diversity Index Calculator

Shannon Diversity Index Calculator: Measure Community Biodiversity

The Shannon Diversity Index is one of the most widely used measures of biodiversity, combining both how many species are present and how evenly individuals are distributed among them into a single number. This calculator computes it directly from your species abundance counts.

The Formula

H = −Σ(p_i × ln(p_i)), where p_i = n_i / N

Worked Example

A community sample has 40, 30, 20, and 10 individuals across four species (100 total).

H = −(0.4ln0.4 + 0.3ln0.3 + 0.2ln0.2 + 0.1ln0.1) = 1.2799

How to Use This Calculator

1. Enter the individual count for each species sampled (at least two species).
2. Click Calculate to get the Shannon Diversity Index.

Related Calculations

Compare against the Simpson's Diversity Index Calculator, an alternative diversity measure that's more sensitive to dominant species.