Biodiversity Index Calculator

Calculate Shannon-Wiener, Simpson's, and Margalef biodiversity indices from species count data for conservation assessment.

Inputs

Total Species Count (S)

Total Individuals (N)

Most Abundant Species Count

Sample Area

hectares

Number of Habitat Types

Tab to move between fields

Results

Shannon-Wiener Index (H')

3.11

Biodiversity Rating

High Biodiversity

Simpson's Diversity (1-D)0.95

Simpson's Reciprocal (1/D)18.18

Pielou's Evenness (J)0.97

Margalef's Richness Index3.86

Berger-Parker Dominance0.16

Species Density2.5 species/ha

Predicted Species (2× area)30

Species Richness25

How to Use This Calculator

Enter the total species count (S) and total individual organisms counted (N) in your sample.
Input the count of the most abundant (dominant) species.
Set the sample area and number of distinct habitat types.
Review the Shannon-Wiener Index (H') and Simpson Diversity to characterize biodiversity.
Use the evenness score to assess how evenly individuals are distributed across species.

How the result changes with Total Species Count (S)

Total Species Count (S)	Shannon-Wiener Index (H')	Biodiversity Rating
501	5.66	Very High Biodiversity
1,751	6.71	Very High Biodiversity
3,250	7.23	Very High Biodiversity
4,500	7.51	Very High Biodiversity

What each input means

Total Species Count (S): Number of distinct species observed in the sample.
Total Individuals (N): Total number of individual organisms counted across all species.
Most Abundant Species Count: Number of individuals of the most abundant species. Used to calculate dominance indices.
Sample Area: Total area surveyed.
Number of Habitat Types: Number of distinct habitat types present (forest, wetland, grassland, etc.).

What each result means

Shannon-Wiener Index (H'): Typical range 1.5-3.5. Higher = more diverse.
Simpson's Diversity (1-D): 0-1 scale. Higher = more diverse.
Pielou's Evenness (J): 0-1 scale. 1 = perfectly even distribution.
Berger-Parker Dominance: Proportion of the most abundant species. Lower = more even.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Total Species Count (S) = 25, Total Individuals (N) = 500, Most Abundant Species Count = 80, Sample Area = 10 = 5 input(s) provided
Calculate Shannon-Wiener Index
Shannon-Wiener Index
3.109 = 3.109
Calculate Biodiversity Rating
High Biodiversity = High Biodiversity
Calculate Simpson's Diversity
Simpson's Diversity
0.945 = 0.945
Calculate Simpson's Reciprocal
Simpson's Reciprocal
18.18 = 18.18

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Conservation

Endangered Species Recovery Calculator

Model population growth from breeding program parameters to predict recovery timeline and genetic diversity retention.

Conservation

Ecosystem Services Value Calculator

Estimate the annual dollar value of ecosystem services including water filtration, pollination, carbon sequestration, and flood control.

Marine Biology

Fish Biodiversity Index Calculator

Calculate Shannon-Wiener diversity (H'), Simpson's index, Pielou's evenness, and Margalef's richness from species abundance data.

Ecology

Species Diversity Index Calculator

Calculate Shannon-Wiener (H'), Simpson's Diversity Index, and evenness from species abundance data for up to 10 species.