Tool
Mid-parent WBV calculator.
Enter a sire and dam WBV for any trait and see the expected progeny value. Works in whatever units the trait uses — just keep both WBVs on the same scale.
A calf’s expected merit is the average of the two parents’ WBVs, because each parent passes on half its genes. Works for any trait — use both WBVs in the same units.
Why it’s the average
Each parent passes half its genes to a calf, so the calf’s expected genetic merit is the average of the two parents’ WBVs. It’s an expectation, not a guarantee — real progeny scatter around the mid-parent value. Learn more in What are WBVs?, WBV accuracy and using WBVs to pick a mating.
Frequently asked questions
How do you calculate a progeny's WBV?
A calf's expected breeding value is the average of the sire's and dam's WBVs for that trait — the mid-parent value — because each parent passes on half its genes. It is an expectation; individual calves vary around it.
Can I compare WBVs from different breeds?
No. WBVs are only comparable within the same breed analysis, because each breed is measured against its own genetic base. Use sire and dam WBVs from the same evaluation, in the same units.
Does a higher WBV always mean a better animal?
Not always — the desirable direction depends on the trait. A lower birth-weight WBV can be preferable for calving ease, for example. Weigh WBVs together in a selection index rather than chasing one trait.