Estimate expected litter size from breed size, age and parity.
Litter size correlates with maternal body size in dogs but is fairly constant in cats. First litters run smaller and size declines after about seven years of age. A radiographic count near day 45 is the only reliable figure, and knowing it beforehand is what makes a retained fetus detectable during whelping.
Litter Size Predictor
Litter size scales with maternal body size, adjusted for age and parity
This is a statistical estimate only. Breeding decisions carry health risks for the mother and offspring and should be made with veterinary advice. An accurate count requires imaging by a veterinarian.
Litter size scales with maternal body size, adjusted for age and parity Litter size correlates with maternal body size in dogs but is fairly constant in cats. First litters run smaller and size declines after about seven years of age.
A radiographic count near day 45 is the only reliable figure, and knowing it beforehand is what makes a retained fetus detectable during whelping.
This calculator takes 4 inputs: Species, Mother's adult weight, Mother's age, Previous litters. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.