Simpsons Diversity Index Calculator

The Simpsons Diversity Index (SDI) measures the biodiversity of a community by calculating the probability that two randomly selected individuals are from different species. This calculator can be used to determine the diversity of ecosystems, communities, or populations.

Input Parameters

Calculation Results

Calculation Formula

SDI = 1 - Σ (n_i * (n_i - 1)) / (N * (N - 1))

Where:
SDI = Simpsons Diversity Index
n_i = number of individuals of species i
N = total number of individuals in the community

Simpsons Diversity Index Calculator Calculator Usage Guide

Learn how to use the Simpsons Diversity Index Calculator calculator and its working principles

How to Use the Calculator

  1. Enter the number of individuals for each species in the input fields. You can add up to 10 species.
  2. Click the "Calculate" button to compute the Simpsons Diversity Index (SDI).
  3. The result will be displayed in the "Simpsons Diversity Index (SDI)" field.
  4. If you want to start over, click the "Reset" button to clear all inputs.

Understanding the Simpsons Diversity Index

The Simpsons Diversity Index (SDI) is a measure of biodiversity that takes into account both the number of species present and the relative abundance of each species. It ranges from 0 to 1, where:

  • A value of 0 indicates no diversity (all individuals belong to a single species).
  • A value of 1 indicates maximum diversity (all individuals belong to different species).

Example Calculation

Suppose you have a community with the following species counts:

  • Species 1: 10 individuals
  • Species 2: 20 individuals
  • Species 3: 30 individuals

Enter these values in the calculator and click "Calculate". The SDI will be approximately 0.8333, indicating a high level of diversity.

Applications of the Simpsons Diversity Index

The SDI is widely used in ecology to assess the biodiversity of ecosystems, communities, or populations. It helps researchers and conservationists understand the health and stability of ecological systems.