COI Calculator
Enter a potential sire and dam to calculate the inbreeding coefficient (COI) of their hypothetical offspring. Uses Wright's Path Coefficient algorithm.
What is COI?
The Coefficient of Inbreeding (COI) measures the probability that two alleles at any given gene locus are identical by descent — i.e. inherited from the same common ancestor. A higher COI means more inbreeding.
- Below 6.25% — generally considered acceptable
- 6.25–12.5% — moderate; consider genetic diversity
- Above 12.5% — high; elevated risk of genetic disorders
Methodology: Wright, S. (1922). Coefficients of inbreeding and relationship. The American Naturalist, 56(645), 330–338.
Register your animals and compute COI across unlimited generations.
Free tier includes up to 50 animals and 3-generation pedigrees. Individual Pro unlocks 8 generations and unlimited animals.