Llama Gestation Calculator (cria due date for llamas & alpacas, about 342 days)

Understanding the llama gestation calculator — concept and principle

This calculator estimates when a pregnant llama or alpaca will give birth (cria) from the mating date, shows the normal window and today's progress, and marks the dates of the spit-off test, the first ultrasound check and when she can conceive again. Camelid breeders use it to plan checks and birthing.

Counting 342 days: with the default inputs the result is May 1, 2027 (expected birth).

How it is calculated

Expected birth = mating date + 342 days.
Normal window = day 332 to day 352 (342 ± 10).
Spit-off test from day 15; ultrasound possible after day 21.
Can conceive again about 14 days after birth (day 342 + 14 = day 356 from mating).
Days pregnant = today − mating; days to due date = 342 − days; week = floor(days ÷ 7) + 1; progress = days ÷ 342.

The principle

Llamas and alpacas carry a cria for about 342 ± 10 days, alpacas a little shorter than llamas; some extension sources quote about 350 ± 14 days. Camelids are induced ovulators: mating triggers ovulation. A female that has ovulated and conceived usually refuses the male from about 15 days after mating, spitting or running away, which is the basis of the spit-off or behaviour test. A transrectal ultrasound can show the pregnancy after about 21 days. Most females can conceive again within 14–21 days after giving birth.

Worked example

Default inputs: mated on May 24, 2026, viewed on Nov 10, 2026.

Expected birth = May 24, 2026 + 342 days = Sat, May 1, 2027.
Window = Wed, Apr 21, 2027 (day 332) to Tue, May 11, 2027 (day 352).
Days pregnant = 170; days to due date = 172; week 25; progress = 170 ÷ 342 = 50%; stage before the normal birth window.
Spit-off from Mon, Jun 8, 2026; ultrasound after Sun, Jun 14, 2026.
Can conceive again from Sat, May 15, 2027.

How to read the result

The spit-off test is a quick, cheap check but not proof; confirm with ultrasound. Because the normal range is wide, plan to watch the female closely from about day 330, and have your vet's number ready.

Common mistakes

Treating a positive spit-off as certain pregnancy.
Using one mating date when the pair ran together for days.
Expecting birth exactly on day 342.
Rebreeding too soon after a difficult birth without a vet check.

Keep in mind: This is an estimate, not a diagnosis. Call your vet if the female strains without progress, shows distress, or goes well past the normal window.

Frequently asked questions

How long is a llama pregnant?

About 342 ± 10 days, roughly 11 to 11½ months.

What is a spit-off test?

A behaviour test from about day 15: a pregnant female usually refuses the male by spitting or moving away.

When can a llama be bred again after birth?

Most can conceive again within 14–21 days after giving birth.

Sources: MSD Veterinary Manual (professional version), "Reproduction of Llamas and Alpacas" · Oklahoma State University Extension, VTMD-9122 (Boileau & Giedt)

Checked 9 Nov 2026. MSD Veterinary Manual (professional version), “Reproduction of Llamas and Alpacas”: gestation ~342 ± 10 days (332–352), rejection of the male about 15 days after mating, transrectal ultrasound after 21 days, conception again within 14–21 days after delivery; Oklahoma State University Extension VTMD-9122 (Boileau & Giedt): about 350 ± 14 days.

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