Inbreeding Coefficient Calculator

The Inbreeding Coefficient Calculator measures how closely related two parents are by calculating the probability that an offspring inherits identical gene copies from a shared ancestor — a key metric in animal breeding, genetics, and livestock management. Enter the names of the sire (father) and dam (mother) along with their parents and grandparents, then select the number of generations (3–6) to analyze. You'll get the Inbreeding Coefficient (F%), Relationship Status, Genetic Diversity Index, and the number of Common Ancestors Found across the pedigree.

Select how many generations to include in the calculation

Results

Inbreeding Coefficient (F)

--

Relationship Status

--

Genetic Diversity Index

--

Common Ancestors Found

--

Results Table

More Biology Tools

Frequently Asked Questions

What is the inbreeding coefficient and why is it important?

The inbreeding coefficient (F) measures the probability that two alleles at any locus are identical by descent. It ranges from 0% (no inbreeding) to 100% (maximum inbreeding). Higher coefficients indicate reduced genetic diversity and increased risk of genetic disorders.

What is considered a safe inbreeding coefficient for breeding?

Generally, coefficients below 6.25% are considered acceptable for most breeds. Coefficients of 12.5% or higher indicate close inbreeding and may increase health risks. Many breed organizations recommend keeping coefficients as low as possible while maintaining breed characteristics.

How many generations should I include in the calculation?

More generations provide more accurate results. A minimum of 3 generations is recommended, but 5-6 generations give better insight into genetic diversity. Deep pedigrees may reveal distant relationships not apparent in shorter pedigrees.

What does it mean if my calculation shows common ancestors?

Common ancestors appear in both the sire's and dam's lineage, indicating some degree of relatedness between the parents. The more recent and frequent these common ancestors, the higher the inbreeding coefficient will be.

Can I use this calculator for any animal species?

Yes, Wright's inbreeding coefficient formula applies to all sexually reproducing species. This calculator works for dogs, cats, horses, livestock, and any other animals with known pedigree data.

What if I don't know all the ancestor names in the pedigree?

Unknown ancestors reduce calculation accuracy. Enter as much pedigree information as available - partial data still provides useful insights. Mark unknown individuals consistently (e.g., 'Unknown Male 1') rather than leaving fields blank.

How does inbreeding affect offspring health and performance?

Moderate inbreeding can help fix desirable traits but may also increase risk of genetic disorders and reduce vigor. Effects include potential fertility issues, immune system problems, and expression of recessive genetic diseases.