Animal Gestation Calculator

Alpaca Gestation Calculator

A alpaca's gestation period is about 345 days, or roughly 11 months and 1 week, though it ranges from 335 to 355 days depending on breed and individual animal.

How to use the alpaca gestation calculator

  1. 1. Choose what you know. Enter the breeding date to get a due date, or switch to the target due date mode to work backwards to the breeding date you need.
  2. 2. Refine the inputs. The calculator uses the 345-day average for this species.
  3. 3. Plan around the range. Use the earliest and latest dates and the milestone timeline to schedule checks, feed changes and preparation of the birthing area.

Calculate a cria due date

What do you know?

Estimated birthing date

Monday, 23 August 2027

Earliest

13 Aug 2027

Latest

2 Sept 2027

345 days remaining0% complete

0 of 345 days elapsed

Milestone timeline

Key Alpaca pregnancy milestones with calculated calendar dates
DayMilestoneDate
14Spit-off test: an open female sits for the male, a pregnant one spits26 Sept 2026
45Ultrasound or progesterone test confirms the pregnancy27 Oct 2026
90Recheck — early embryo loss is common in alpacas11 Dec 2026
240Clostridial booster so the cria gets antibodies via colostrum10 May 2027
300Shear or crutch her and lift the ration for the final growth phase9 Jul 2027
335Earliest normal birthing — start morning checks13 Aug 2027
345Expected birthing (unpacking)23 Aug 2027

What to do next

How long is a alpaca's gestation period?

The average is 345 days from breeding to birthing, about 11 months and 1 week. Anything between 335 and 355 days is normal, and a typical litter is 1 cria. Treat the calculated date as the middle of that window rather than a fixed appointment.

Alpaca gestation table: breeding date to birthing date

Breeding dates one week apart with the matching birthing date at 345 days.

Twelve sample Alpaca breeding dates and their calculated due dates
Breeding dateExpected birthing date
12 Sept 202623 Aug 2027
19 Sept 202630 Aug 2027
26 Sept 20266 Sept 2027
3 Oct 202613 Sept 2027
10 Oct 202620 Sept 2027
17 Oct 202627 Sept 2027
24 Oct 20264 Oct 2027
31 Oct 202611 Oct 2027
7 Nov 202618 Oct 2027
14 Nov 202625 Oct 2027
21 Nov 20261 Nov 2027
28 Nov 20268 Nov 2027

Working backwards from a target birthing date

If you want crias on the ground in a particular week, switch the calculator to target date mode and enter the date you are aiming for. It subtracts 345 days to give the breeding date to book, plus the earliest and latest service dates that still land inside your window.

Alpaca gestation calculator FAQs

How long is an alpaca pregnant?

About 345 days, roughly 11 and a half months, with a normal range of 335 to 355 days. Because alpacas ovulate in response to mating, the service date is usually exact and the calculated due date is reliable.

What is a spit-off test?

Around 14 days after mating the female is reintroduced to a male. A pregnant female spits, kicks and refuses him; an open female sits down to be mated. It is a cheap, practical first check, though it is not a substitute for ultrasound.

What time of day do alpacas give birth?

Almost always in the morning, usually between 7am and 2pm. It is a strong species habit that lets the cria dry off and stand before the cold Andean night, and it survives in domesticated herds worldwide.

How will I know birthing is starting?

Alpacas hide it well. Look for repeated trips to the dung pile with little result, humming, separation from the herd, restlessness and rolling. Once active straining begins the cria should appear within about 30 minutes — nose and both front feet first.

When should I call a vet during an alpaca birth?

If she strains for 30 minutes with nothing visible, if you see a head without both feet or feet without a head, or if the cria is not up and nursing within three hours. Alpacas birth quickly, so a slow birth is a genuine emergency.

More gestation pages

Livestock gestation chart