Boa Constrictor Prey Size Chart & Calculator
The right prey size is the single most important feeding decision for a boa constrictor. Prey should be roughly 10-15% of the snake's body weight, or about the width of the snake's widest point. The chart below matches each weight class to a standard frozen prey item.
| Snake weight | Prey item | Prey weight | Frequency |
|---|---|---|---|
| under 300 g | Hopper mouse or rat pup (15–40g) | ~25 g | every 7 days |
| 300–800 g | Weaned rat or small rat (40–80g) | ~60 g | every 10 days |
| 800–2,000 g | Small–medium rat (80–150g) | ~110 g | every 14 days |
| 2,000–4,000 g | Large rat or small rabbit (150–450g) | ~300 g | every 21 days |
| 4,000 g and up | Rabbit or guinea pig (450g+) | ~600 g | every 28 days |
What to feed
Boas are carnivores taking appropriately-sized rats and, for large adults, rabbits or similar. Prey should be roughly 10-15% of body weight or the width of the snake's midbody. Frozen-thawed is the recommended standard.
Frequently asked questions
What size prey should a boa constrictor eat?
Prey should weigh roughly 10-15% of the boa constrictor's body weight, or be about as wide as the thickest part of the snake. Use the chart and calculator above to match your snake's exact weight.
What happens if the prey is too big?
Oversized prey can cause regurgitation, stress or refusal. When in doubt, size down — a slightly small meal is far safer than one that's too large.
How often should I feed a boa constrictor?
Juveniles every 7-10 days, adults every 2-4 weeks, and very large adults sometimes less. Feeding frequency should drop steadily as the boa matures.