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Shannon Diversity Index Calculator

Compute the Shannon index and evenness of a community.

Inputs

Results

Shannon index H′1.279854
Maximum H′ (ln S)1.386294
Evenness0.9232197

Chart

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Describe what you want to find — “species evenness” — and jump to the right calculator.

How to use the shannon diversity index calculator

Compute the Shannon index and evenness of a community. Enter counts per species in the field above; the shannon index h′, maximum h′ (ln s), evenness are computed instantly and plotted on the chart so you can see how the answer changes.

Common searches this calculator answers include “species evenness”, “ecological diversity”, “shannon wiener”, “calculate shannon diversity index”, “find shannon index h′”.

Formula

Shannon index H′ = -sum(n.map(function(v){return v / sum(n) × ln(v / sum(n))}))
Maximum H′ (ln S) = ln(len(n))
Evenness = [Shannon index H′] / [Maximum H′ (ln S)]

Variables

  • n — Counts per species

Worked example

With counts per species = 10,20,5,15, the calculator gives shannon index h′ ≈ 1.279854; maximum h′ (ln s) ≈ 1.386294; evenness ≈ 0.9232197.

Frequently asked questions

What is the shannon diversity index calculator used for?

Compute the Shannon index and evenness of a community. It helps with questions such as “species evenness”, “ecological diversity”, “shannon wiener”.

What is the formula for the shannon diversity index calculation?

Shannon index H′ = -sum(n.map(function(v){return v / sum(n) × ln(v / sum(n))})). Maximum H′ (ln S) = ln(len(n)). Evenness = [Shannon index H′] / [Maximum H′ (ln S)]. Here n is counts per species.

What inputs do I need for the shannon diversity index calculator?

You need counts per species. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.

How do I use the shannon diversity index calculator?

Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.

Is the shannon diversity index result exact?

Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.

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