Reptile Feeding Schedule Calculator
Calculate the appropriate prey item weight range and recommended feeding frequency for your pet snake or reptile based on body weight and age stage. The prey size guideline (10-15% of body weight for adults, 15-20% for juveniles) is drawn from published herpetological husbandry literature and guidelines from the Association of Reptilian and Amphibian Veterinarians (ARAV). These are starting-point guidelines; observe your individual animal and consult a reptile veterinarian for species-specific advice.
Prey size formula (ARAV guidelines)
Adult prey min (g) = reptile body weight (g) x 10%
Adult prey max (g) = reptile body weight (g) x 15%
Juvenile prey range (g) = reptile body weight (g) x 15% to 20%
These percentages are published husbandry guidelines from the Association of Reptilian and Amphibian Veterinarians (ARAV) and widely cited in reptile care texts including "Reptile Medicine and Surgery" (Mader, 2006, Elsevier). The guidelines apply primarily to snakes; lizards and other reptiles may have different dietary requirements.
Feeding frequency by age stage
- Hatchling / juvenile (under 12 months): every 5-7 days
- Sub-adult (12-24 months): every 7-10 days
- Adult (over 24 months): every 10-14 days
- Large constrictors (over 2 kg): every 14-21 days
- Note: always allow full digestion (no handling for 48-72 hours after feeding) before offering the next meal.
Reptile feeding schedule calculator: frequently asked questions
How do I choose the right prey size for my snake?
Published herpetological husbandry guidelines (including those from the Association of Reptilian and Amphibian Veterinarians, ARAV) recommend prey items that are approximately 10-15% of the snake's body weight for adults, and up to 15-20% for juveniles in active growth. The prey item width should not exceed the widest part of the snake's body.
How often should I feed my snake?
Feeding frequency depends on species, age, and prey size. Hatchlings and juveniles (under 12 months) are typically fed every 5-7 days. Sub-adults feed every 7-10 days. Adult snakes generally feed every 10-14 days. Larger prey items can extend intervals. Always observe post-feeding behaviour to confirm prey is digested before offering the next meal.
What is the 10-15% body weight rule?
This rule is a widely cited guideline in reptile husbandry literature. A prey item weighing 10-15% of the snake's body weight provides adequate nutrition without overloading digestion. For a 1,000 g python, a suitable prey item weighs 100-150 g (a medium mouse or small rat).
Should I feed live or pre-killed prey?
The ARAV and most veterinary herpetologists recommend feeding pre-killed (frozen-thawed or fresh-killed) prey to avoid injury to the snake. Live rodents can bite and scratch, causing serious wounds. Pre-killed prey also eliminates disease transmission risk from live feeders.
Why is my reptile refusing food?
Common reasons include: shedding (ecdysis) phase, breeding season, temperature too low (below optimal range), incorrect humidity, stress from handling or husbandry issues, illness, or insufficient hiding space. If a reptile refuses food for more than 4-6 weeks, consult a reptile veterinarian.
Official sources
- Association of Reptilian and Amphibian Veterinarians (ARAV): ARAV Husbandry and Care Resources.
- Mader DR (ed.), "Reptile Medicine and Surgery" (2006), Elsevier: standard veterinary herpetology reference for prey size guidelines.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.