Species Richness Calculator
Estimate how biologically diverse a habitat is by turning a simple species count and individual count from your survey into standard richness measures.
What is species richness?
Species richness is simply the number of different species found in a given area or survey sample. It is one of the most basic and widely used measures of biodiversity, used by ecologists, students, and citizen-science groups to compare habitats or track change over time.
How this calculator works
Enter the number of distinct species you identified (S) and the total number of individual organisms you counted across all species (N). The calculator reports your raw species richness and also calculates Margalef’s richness index, D = (S – 1) / ln(N), a standard formula that adjusts richness for sample size so that surveys with different numbers of individuals can be compared more fairly.
- S = number of species observed
- N = total number of individuals counted
- D = Margalef’s richness index
This tool is for general educational and field-study planning purposes. Real biodiversity assessments should also account for survey effort, detection probability, and sampling method.