Rabbit Pregnancy Calculator

In 2026, an ARBA-licensed Holland Lop breeder in Ohio records every breeding in a paper log: breeding date, palpation result, nest-box date, kindling count, kit weights at day 14 and day 35. The horizontal timeline above is the digital equivalent — a known-good gestation window with breed-specific milestones, used by registered breeders, RWAF rescues, and pet owners with accidental pregnancies.

Rabbit reproductive biology is unusual among mammals. Rabbits are induced ovulators — they do not have an estrous cycle. Mating itself triggers ovulation 9-13 hours after copulation. This is why a single fall-off mating produces conception 70-80% of the time, far higher than any spontaneous-ovulator species (dogs, cats, primates).

Gestation runs 28-33 days. The variability comes from breed, litter size, and doe age. Larger litters tend toward shorter gestation; first-time does (gilt-equivalent) often kindle on the later side. The average across all breeds is 31 days. The 28-33 window is well-documented in ARBA breed standards, OSU Extension, and Cornell's Department of Animal Science rabbit science primer.

Pseudopregnancy (false pregnancy) is the largest source of confusion for new breeders. After an infertile mating or even after being mounted by another doe, a doe can produce all the visible signs of pregnancy — nesting, fur pulling, weight gain — but no kits. Pseudopregnancy lasts 16-18 days and resolves on its own. Day 17 on this timeline marks the cutoff; signs continuing past day 18 indicate a real pregnancy.

Palpation is the only reliable early detection. From day 10-14, an experienced hand feels 1.5-2 cm marble-sized fetuses along both uterine horns. Earlier palpation is unreliable (embryos too small); later palpation risks stressing the doe and causing re-absorption. New breeders should learn palpation on a non-pregnant doe first under supervision — the technique is in every ARBA breeder's manual and on House Rabbit Society's educational pages.

Nest-box timing is the single most-asked breeder question. RWAF and ARBA both say day 14 — earlier and the doe litter-boxes it; later and she kindles outside. The box must be wood or metal (plastic gets chewed and ingested), 10x14x8 inches for medium breeds, 14x18x10 inches for giants. Line with straw and hay; never cloth or paper towels (suffocation risk for blind kits).

Postpartum estrus is the family-planning challenge. Does can become pregnant within 24 hours of kindling — wild rabbits run back-to-back litters all summer this way. House Rabbit Society and RWAF strongly recommend spaying does not actively in a breeding program. Intact does also carry an 80%+ lifetime risk of uterine adenocarcinoma. For accidental pregnancies, after weaning at 8 weeks, the doe should be spayed — see related rabbit age calculator for senior-care timing.

For diet during pregnancy, see the sibling rabbit food calculator — late-gestation does need 16-18% crude protein pellets, alfalfa hay for calcium, and unlimited water. The same calculator covers post-kindle nursing-doe rations (50%+ above adult intake).