Shannon Diversity Index
Compare abundance diversity and evenness from category counts.
Your numbers
Shannon diversity H
Use consistent units. The result follows the assumptions you enter.
Scenario comparison
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Formula
Use H = −Σpᵢln(pᵢ) and J = H/ln(S). pᵢ is each positive category count divided by total count, and S is category count. ln is natural logarithm. A single category uses the convention J = 1.
Compare abundance diversity and evenness from category counts.
Worked example
- Positive category counts
- 10, 10, 10
- Shannon diversity H
- 1.09861228867
- Evenness
- 1
- Effective categories
- 3
Scope and limitations
Use consistent units. The result follows the assumptions you enter.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: ce2e116d5108 · Example checked: