Feel free to move this if it should go somewhere else :/

I've been studying animal nutrition and learned a really cool formula from the IWRC manual to figure out how many kcal / day and grams per feeding various animals need, and decided to try it on my snake, and it actually worked! It's a lot of math, but it's here if your interested (the 10-15% is way easier)

The formula: taxonomic constant x (weight in kg)^0.75 x 1.5 x physiological factor = kcal/24 hours
- the taxonomic constant for ectotherms is 10
- I used the 'growth' range of the physiological factor which is 1.5 to 3.0 (it changes if the animal is sedentary/sick/injured/trying to gain or loose wt)
- my snake weighs 345g or 0.345 kg
- he eats whole rats that are between 10g and 50g and the break down for the nutrition of this prey is (prey size and type changes all these factors too):
Dry Matter 30.00%, protein 16.83%, fat 8.25%, calcium 0.62%, phosphorus not given, g/kcal 1.67


Step 1: BMR (basal metabolic requirement) = taxonomic constant x (weight in kg)^0.75
(10)x(0.345 kg)^0.75
(10)x(.4502)
BMR=4.502

Step 2: MMR (maintenance metabolic requirement) = BMRx1.5
(4.502)x(1.5)
MMR= 6.753

Step 3: Kcal/day: Calculate the animal's daily requirements (range) based on physiological factor
MMR x physiological factor
(6.753)x(1.5) (6.753)x(3.0)
=10.1295 kcal/day =20.259 kacl/day

Step 4: Convert kcal/day to g/day
(10.1295 kcal/day) / (1.67 kcal/g) = 6.0656 g/day
(20.259 kcal/day) / (1.67 kcal/g) = 12.1311 g/day

Since I am feeding every 5 days, you multiply the g/day by 5 to get the total grams of rat he needs per feeding.
(6.0656 g/day)x(5)= 30.328g or ~30g
(12.1311 g/day)x(5)= 60.6555g or ~61g

Now this is close to a 9% to 18% of body weight of prey per feeding, rather than the much more common 10-15% of body weight of prey per feeding, but I was surprised at how close it came. This might be where this 'rule' for a growing snake came from...I'm not really a math nerd, I promise.