Enter the number of species in the sample and the total number of species in the population into the calculator to determine the Dominance Index. This calculator can also evaluate any of the variables given the others are known.

Dominance Index Formula

The following formula is used to calculate the Dominance Index.

DI = (S / T) * 100

Variables:

  • DI is the Dominance Index (%)
  • S is the number of species in the sample
  • T is the total number of species in the population

To calculate the Dominance Index, divide the number of species in the sample by the total number of species in the population. Multiply the result by 100 to get the Dominance Index in percentage.

What is a Dominance Index?

A Dominance Index is a statistical measure used in ecology to quantify the biodiversity of a habitat. It represents the degree to which a species dominates within a particular ecological community. The index is calculated based on the relative abundance of different species within the community. A high dominance index indicates that one or a few species dominate the community, while a low dominance index suggests a more even distribution of species.

How to Calculate Dominance Index?

The following steps outline how to calculate the Dominance Index:


  1. First, determine the number of species in the sample (S).
  2. Next, determine the total number of species in the population (T).
  3. Next, gather the formula from above = DI = (S / T) * 100.
  4. Finally, calculate the Dominance Index.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Number of species in the sample (S) = 15

Total number of species in the population (T) = 50