Due date calculator
Pick the species and the day of mating or insemination. You get the likely birth date and how many days are left.
Likely birth
Thursday, April 29, 2027
183 days to go
283-day gestation
100 of 283 days
This is an average date. A birth a few days early or late is normal; watch the animal from a week or two before.
How it works
How we work it out
We add the average gestation length for the species to the day of mating: cow 283, sow 114, ewe 147, goat 150, mare 340, llama and alpaca 345, doe rabbit 31. These are the same days the Ganaderos app uses to work out the due date, so the dates match.
Why it can vary
Gestation changes with breed, the age of the mother, litter size and the sex of the calf. In cows a week either side is normal; in mares, several weeks.
Common questions
- How many days is a cow pregnant?
- About 283 days on average, roughly nine months and ten days. It varies by a few days with breed: zebu breeds tend to run a little longer than European dairy breeds.
- How long is a sow pregnant?
- About 114 days. The farm rule is three months, three weeks and three days.
- And a ewe or a goat?
- A ewe about 147 days and a goat about 150, roughly five months.
- Which day do I use if there were several matings?
- The last mating or service. If you do not know which one took, work out both the first and the last and watch the animal across that window.