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Compute Shannon H′ from species counts with H′max and Pielou evenness, in ln, log₂, or log₁₀ base.
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Fill in the form, run the tool, and review the result in one place.
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Tool usage guide
Compute Shannon diversity H′ from species abundance counts, along with richness S, total N, H′max, and Pielou evenness J. Choose ln, log₂, or log₁₀ as the logarithm base.
Background
A 100-individual vegetation sample contains five species with counts 40, 25, 20, 10, and 5.
Problem
Need H′, H′max, and Pielou J in natural-log units for a lab report.
How to use
Paste one count per line and leave logarithm base set to ln.
40
25
20
10
5Outcome
H′ = 1.4150 (ln) from S = 5 and N = 100. H′max = 1.6094 and J = 0.8792 — a moderately even community.
Background
A plot is dominated by two species at 60 and 40 individuals (N = 100).
Problem
Check whether low H′ comes from dominance or from having only two species.
How to use
Enter 60 and 40 on separate lines and keep base ln.
60
40Outcome
One abundance per species. Separate values with new lines, commas, or spaces. Species names are not required.
Richness S, total N, proportions, Shannon H′, H′max, Pielou evenness J, the log base, and a brief evenness interpretation.
J = H′ / H′max, where H′max is log(S). J runs from 0 to 1; J = 1 means all species are equally abundant.
Use ln for standard Shannon–Wiener reporting. Use log₂ for bits per species. Use log₁₀ when that unit is required.
H′ increases with both richness and evenness. Low S caps H′ even when evenness is high, so compare communities with similar S.
H′ = 0.6730 with H′max = 0.6931 and J = 0.971. Evenness is high; diversity is limited by richness, not dominance.
Background
A methods section asks for Shannon diversity in bits per species rather than nats.
Problem
Convert the same abundance list to log₂ units while still reporting H′max and J.
How to use
Enter the species counts as usual, then set logarithm base to log₂.
Outcome
H′, H′max, and Pielou J are returned in log₂ (bits per species) for the same S, N, and proportions.