Goat gestation: when is my doe due?
Type the day the doe was bred. The goat gestation calculator gives the estimated kidding date, the normal kidding window, how many days along she is today, and when to watch for heat if she did not settle.
- Estimated kidding date
- January 1, 2027
Your doe is due to kid about January 1, 2027, between December 29, 2026 and January 6, 2027.
- Earliest normal kidding date
- December 29, 2026
- Latest normal kidding date
- January 6, 2027
- Days along
- 60
- Days to the estimated kidding date
- 90
- Where she is now
- Day 60 of about 150: 90 days to the estimated kidding date.
- Next heat if she did not settle
- August 25, 2026
Answer for the example date Saturday, October 3, 2026. It changes to today's date when the page loads.
Estimated kidding date: January 1, 2027. Your doe is due to kid about January 1, 2027, between December 29, 2026 and January 6, 2027.
How to calculate
Computes a doe’s kidding date from the breeding date (150 days), the normal kidding window of 147 to 155 days, how many days along she is, and when to watch for heat if she did not settle.
Example with the default inputs (Breeding date August 4, 2026, Today’s date October 3, 2026) on the example date Saturday, October 3, 2026: Your doe is due to kid about January 1, 2027, between December 29, 2026 and January 6, 2027.
Method: Kidding date = breeding date + 150 days; normal window = breeding date + 147 to 155 days; next heat = breeding date + 21 days.
- The estimate is the Merck Veterinary Manual’s average gestation of 150 days; the window of 147 to 155 days is from Alabama Extension.
- Days count from the breeding date as day 0. Breed, the number of kids and the doe’s age change the length a little.
- A doe that did not settle comes back into heat about one estrous cycle (21 days) after breeding.
Worked examples
Each example is checked against the calculator on every build.
- Breeding date 2026-10-01, Today’s date 2026-12-01 gives Estimated kidding date 2027-02-28, Earliest normal kidding date 2027-02-25, Latest normal kidding date 2027-03-05, Days along 61, Days to the estimated kidding date 89, Next heat if she did not settle 2026-10-22, Where she is now Day 61 of about 150: 89 days to the estimated kidding date..Source: Merck Veterinary Manual, Breeding and Parturition of Goats (gestation in goats lasts an average of 150 days; the estrous cycle averages 21 days), https://www.merckvetmanual.com/management-and-nutrition/preventative-health-care-and-husbandry-of-goats/breeding-and-parturition-of-goats (retrieved 2026-10-03); Alabama Cooperative Extension System, Reproductive Management: Dairy Goats and Sheep (lambing and kidding generally occur 147 to 155 days after conception), https://www.aces.edu/blog/topics/sheep-goats/reproductive-management-dairy-goats-and-sheep/ (retrieved 2026-10-03); 1 October 2026 + 147, 150 and 155 days
- Breeding date 2027-10-15, Today’s date 2028-03-16 gives Estimated kidding date 2028-03-13, Earliest normal kidding date 2028-03-10, Latest normal kidding date 2028-03-18, Days along 153, Days to the estimated kidding date -3.Source: Merck Veterinary Manual, Breeding and Parturition of Goats (gestation in goats lasts an average of 150 days; the estrous cycle averages 21 days), https://www.merckvetmanual.com/management-and-nutrition/preventative-health-care-and-husbandry-of-goats/breeding-and-parturition-of-goats (retrieved 2026-10-03); Alabama Cooperative Extension System, Reproductive Management: Dairy Goats and Sheep (lambing and kidding generally occur 147 to 155 days after conception), https://www.aces.edu/blog/topics/sheep-goats/reproductive-management-dairy-goats-and-sheep/ (retrieved 2026-10-03)
How it works
The calculator adds whole days to the breeding date:
| Output | Days after breeding | Source |
|---|---|---|
| Estimated kidding date | 150 | Merck Veterinary Manual, average gestation |
| Earliest normal kidding date | 147 | Alabama Extension |
| Latest normal kidding date | 155 | Alabama Extension |
| Next heat if she did not settle | 21 | Merck Veterinary Manual, average estrous cycle |
- Days along = whole days from the breeding date to today’s date. The breeding date is day 0.
- Days to the estimated kidding date = 150 − days along. It is negative once the date has passed.
- Where she is now, by days along (d): past the latest normal date when d is more than 155 (“Day d: past the latest normal kidding date (day 155). Call your vet.”); in the kidding window when d is from 147 to 155 (“Day d: in the kidding window (days 147 to 155).”); otherwise “Day d of about 150: (150 − d) days to the estimated kidding date.”
Rules. Today’s date may not be before the breeding date: then there is no answer and the page says so. Both dates are from 1 January 1900 to 31 December 2200. Calendar days count leap days (2028 has 29 February).
Output format. Dates show as month, day and year. Days along and days to the kidding date are whole numbers.
Worked examples by hand
Bred on 1 October 2026, counted on 1 December 2026. + 147, 150 and 155 days = 25 February, 28 February and 5 March 2027. Next heat: + 21 days = 22 October 2026. From 1 October to 1 December is 30 + 31 = 61 days, so 150 − 61 = 89 days to go.
Bred on 15 October 2027, counted on 16 March 2028. 2028 is a leap year. + 147, 150 and 155 days = 10, 13 and 18 March 2028. From 15 October to 16 March is 16 + 30 + 31 + 31 + 29 + 16 = 153 days, so 150 − 153 = −3 days: the estimate passed 3 days ago, and she is in the kidding window.
Other questions people ask
How long is a goat pregnant?
About 150 days, or 5 months. The Merck Veterinary Manual gives an average of 150 days. Alabama Extension says kidding generally comes 147 to 155 days after conception.
How is the kidding date worked out?
The calculator adds 150 days to the breeding date. The earliest and latest normal dates add 147 and 155 days. A doe bred on 1 October 2026 is due about 28 February 2027.
What if I do not know the exact breeding date?
Use the first day the buck was with the doe for the earliest date, and the last day for the latest. The doe is most likely bred during a heat, which lasts about 36 hours.
When will she come back into heat if she is not pregnant?
The goat estrous cycle averages 21 days, so watch for heat about 21 days after breeding. The calculator shows that date. No heat then is a first sign that she settled.
What if my doe goes past the latest date?
Call your vet. A doe past day 155, or one that strains for a long time without a kid, needs a check.
Do breed and litter size change the date?
A little. Small breeds and does with several kids tend to kid a few days earlier. Merck notes that kids born before day 144 may not survive.