Can counts be percentages?

Yes, if all values use the same scale and are positive.

Does species order matter?

No. The calculator sorts rows by abundance for easier reading.

Enter species abundance counts and calculate Shannon H', evenness, richness, and each species contribution.

Answer

1.2528

Shannon index H'

Evenness: 0.9037

Species richness: 4

Total individuals: 100

Effective species: 3.5001

SpeciesCount

Examples

Dominant species

Species A · 42%

Species contributions

Species	Count	Proportion	Contribution to H'
Species A	42	42%	0.3644
Species B	31	31%	0.3631
Species C	18	18%	0.3087
Species D	9	9%	0.2167

H' = -sum(p_i x ln(p_i)); evenness = H' / ln(S)

p_i is each species' share of all individuals. S is species richness.

Symbol	Variable	Description
p_i	Species proportion	Species count divided by total individuals.
S	Richness	Number of species with positive counts.
H'	Shannon index	Diversity value combining richness and evenness.

1
Enter species counts
Add each species or category with its abundance count.
2
Read H' and evenness
Higher H' usually means greater diversity; evenness shows how balanced the counts are.
3
Check contributions
The table shows each species' proportion and contribution to H'.

Use these values when reporting community diversity.

Result	Meaning
H'	Shannon diversity index
Evenness	How evenly individuals are distributed among species
Effective species	exp(H'), an intuitive diversity equivalent

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