Boa Constrictor Gestation Calculator

Boa constrictor gestation averages 110 days, with a normal range of 100–120 days from confirmed ovulation to birth.

Add 110 days to the confirmed ovulation date (visible as a mid-body swelling). Use the calculator above for an exact expected birth date and the full 100–120 day range.

Boa constrictors are live-bearers (viviparous), giving birth to fully-formed neonates after internal gestation, while most pythons are egg-layers (oviparous) that lay eggs the female then broods by coiling around them. This is the single biggest reproductive difference between the two groups.

Ovulation appears as a visible swelling roughly a third of the way down the body, sometimes called a 'golf ball' or mid-body bulge, typically 2–4 weeks after successful breeding. A post-ovulation shed usually follows within about 2–3 weeks.

Gravid females typically shed again roughly 3–4 weeks before giving birth — commonly called the 'pre-birth shed' — a reliable sign that birth is approaching within that window.

A litter typically contains 10 to 65 neonates, averaging around 25, making boa constrictors one of the more prolific live-bearing snakes.

House neonates individually in a warm, humid enclosure (basking area around 88–92°F). Most neonates have their first shed within 1–2 weeks of birth, and typically won't accept their first meal (appropriately sized pinky or fuzzy mice) until after that shed.

At 110 days, boa constrictor gestation is much longer than the ball python's 57-day egg incubation or the corn snake's 60-day incubation, reflecting the added time live-bearing species need to fully develop young internally before birth.