Body Condition Index (BCI) Calculator
Estimate the body condition of animals using the ratio of body weight to a power-transformed length measurement. Used in wildlife biology, fisheries, and ecological studies.
Body Condition Index (BCI)
intermediateEstimate body condition from weight and length measurements
Formula
BCI = weight / length^b Ć k
How It Works
Body Condition Index (BCI) quantifies an animal's energy reserves relative to its body size. Higher values indicate better condition (more mass for a given length). The scaling exponent (b) typically ranges from 2.5-3.5.
BCI = (Weight / Length^b) Ć k
Common formulas: Fulton's K (fish): K = 100 Ć W/LĀ³. Body Mass Index (birds): BCI = W/L^2.5 Ć 100.
Frequently Asked Questions
What scaling exponent should I use?
For fish (Fulton's K): b=3, k=100. For birds (body mass index): b=2.5, k=100. For mammals: b=3, k=100. Research the specific b-value for your species from the literature.
What does a high BCI indicate?
Higher BCI indicates better nutritional status, more energy reserves, and generally healthier individuals. Animals with low BCI may be stressed, diseased, or experiencing food scarcity.