Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Uses natural logarithms and observed abundances. Zero-count species are excluded; no correction for sampling effort or unseen species.
Example Calculation
- Observed species counts: 10,10,10,10
Four equally abundant species have H=ln(4)≈1.3863, effective species 4 and evenness 1.
Frequently asked questions
How do I use this calculator?
Enter observed species counts. The result updates automatically. Use Reset to restore the example values.
What method does it use?
H=−Σpᵢ ln pᵢ; effective species=exp(H); evenness=H/ln(S).. Uses natural logarithms and observed abundances. Zero-count species are excluded; no correction for sampling effort or unseen species.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.