Snake Feeding Calculator

How it works

Target prey weight (g) = snake weight × prey ratio ÷ 100 · Feeder = largest standard rodent size at or below the target · Frequency scales with snake size

Snakes are fed by matching a single prey item to a fraction of the snake's body weight — commonly 10–15%, dropping toward 8–10% for large adults that no longer grow quickly. The old "as wide as the thickest part of the snake" rule of thumb tracks this same target because rodent weight rises with girth. Feeder rodents are sold in standard size classes (pinky, fuzzy, hopper, weanling, adult mouse, then rat pup through large rat), so the practical step is to pick the class that lands at or just below your target weight rather than one that overshoots. Feeding frequency stretches out as a snake grows: hatchlings eat every 5–7 days, mid-size juveniles weekly, and large adults every 10 days to a few weeks. A correct meal leaves a gentle bulge that is gone within a day or two — a persistent large lump means the prey was too big.

Worked example

A 400 g snake fed at 12% of body weight targets 400 × 0.12 = 48 g of prey. The largest standard feeder at or below 48 g is a rat weanling at about 45 g, offered roughly every 7–10 days for a snake this size.

Frequently asked questions