Species Richness Calculator
Estimate total species richness using the non-parametric Chao1 estimator based on observed species, singletons, and doubletons.
Input Parameters
Enter details for calculation.
Estimated Species Richness (Chao1)
Expert Tip
The Chao1 estimator is ideal for sampling data. It uses rare species (singletons and doubletons) to estimate how many species were missed during sampling.
Calculation Methodology & Details
Formula
F1 measures singletons (species counted once), F2 measures doubletons (species counted twice). If F2 is zero, a bias-corrected equation is automatically applied.
Important Disclaimer
The calculations provided are for educational and general planning guidelines only. They do not replace professional laboratory or environmental analysis or certified scientific advice.
How to Estimate Richness
Steps to use the Chao1 ecological model:
Count Species
Record the total number of distinct species observed (S_obs) in your sample.
Identify Rarities
Count how many species are represented by only 1 individual (F₁) and 2 individuals (F₂).
Run Chao1 Estimation
The calculator estimates total richness including unrecorded species.