Ball Python Weight Chart by Age (and How It Sets Rat Size)

Here's a ball python weight chart in one line. A vet-reviewed chart from The Vet Desk lists about 45 to 80 grams for hatchlings. It shows 500 to 900 grams at 1 year and 900 to 2,000 grams at 3 years. Adults 5 and up run 1,000 to 3,000 grams. Females usually weigh more than males. Pick rat size from your snake's real weight, not its age.

Got a scale reading already? Text Mike your snake's weight at (520) 451-4380 and he'll match a size.

Ball python weight chart by age

These ranges come from a growth chart on The Vet Desk, reviewed by veterinarian Dr. Ashley Darby. The last column shows the feeder that fits each weight at the 10% rule many keepers use.

A note on the hatchling row. The same Vet Desk page also says hatchlings "start life weighing just 100 grams on average." That doesn't match its own chart. So treat the hatchling numbers loosely and weigh your own snake.

Mike's smallest size is the Hopper mouse (7 to 12 g). It fits snakes around 70 to 120 grams. A tiny hatchling may need a smaller mouse than Mike sells.

Why is age a weak guide for ball python weight?

Look at the 1-year row. It runs from 500 to 900 grams. One yearling can weigh almost twice as much as another.

The Vet Desk says growth rates vary a lot from snake to snake. It also says "early life nutrition impacts their growth rate." So a snake that ate less as a baby may stay on the small side.

Snakes also stop eating for stretches. ReptiFiles says young adult females around 1,000 grams are known for long fasts. Keepers call it "the Wall." Males often fast for a while in breeding season, too.

So use the chart as a rough map. Your scale is the real answer.

Do male and female ball pythons weigh differently?

Yes. Females usually weigh more.

The Vet Desk says females "typically occupy the higher end of the range and the males the lower end." It adds that females are "stockier and heavier than males." Females often reach 4 to 5 feet long. Males usually top out at 3 to 4 feet.

So a 3-year-old male near 1,000 grams can be right on track. A 3-year-old female near 2,000 grams can be too.

Ball python weight to rat size: the feeding chart

This is the part most weight charts skip. Here's how snake weight lines up with Mike's feeder sizes, using the 10% rule:

Prices are per animal, plus Arizona sales tax (6.1%). Sold as feeders, not pets. Buy 10 or more and each one is 10% off. It's 20% off at 25 and 30% off at 50 or more.

What about 300 to 450 grams? That's the gap between one Adult mouse and a Small rat. Many keepers feed two smaller mice in one meal, or a rat from the low end of the Small range. Our guide to switching a ball python from mice to rats covers this gap step by step.

Is 10% right for adults? It's a common starting point. ReptiFiles suggests 10% to 15% of body weight. It also says to keep tabs on your snake's shape and adjust meal size and how often you feed. So 10% is a place to start, not a fixed rule. A grown snake that's getting round may need smaller meals or longer gaps. Body shape tells you more than any chart.

For the full sizing guide, see what size rat for a ball python. For timing, see how often to feed a ball python.

Not sure which size fits? Call or text Mike at (520) 451-4380 with your snake's weight. He'll match it to a size. You can also see every size on the live feeder rats and live feeder mice pages.

How do I weigh my ball python at home?

You need a digital scale that reads grams. A kitchen scale works for most ball pythons.

1. Weigh the empty container. Use a tub or a cloth snake bag. Write that number down.
2. Put your snake in and weigh again. The Vet Desk suggests this bag method. It keeps the snake from sliding off the scale.
3. Subtract. The second number minus the first is your snake's weight.
4. Weigh before a meal. A fresh meal adds weight and throws off the number.
5. Log it. Keep a simple list of dates and weights.

How often? ReptiFiles says to weigh a ball python once a week "for best results." Once a month works for spotting longer trends. The point is to see the line over time, not one number.

Is my ball python underweight?

Check the shape and the trend.

ReptiFiles describes a well-fed ball python's cross-section like "a melted Hershey Kiss." It's round on the sides with a gentle peak at the spine. Here's how to read it:

• Spine sticks out sharply: your snake likely needs more food.
• No spine visible at all: your snake likely needs less.
• Round sides, gentle peak: about right.

Watch the scale too. ReptiFiles says a fast is no cause for alarm if your snake isn't losing more than 10% of its body weight. If it drops past that, or shows other signs of illness, see a reptile vet. To find one, a vet column in REPTILES magazine points to the Association of Reptilian and Amphibian Veterinarians vet directory (arav.org).

Not eating at all? Read why a ball python won't eat and how long a ball python can go without eating.

Weigh first, then pick the rat

A ball python weight chart gives you a range. Your scale gives you the answer. Weigh your snake, find its row, and pick the feeder that fits.

Mike breeds live feeder rats and mice in the Tucson area, sized by grams. No shipping. No freezer to fill. Call or text Mike at (520) 451-4380 with your snake's weight, and he replies the same day. The feeder size guide lists every size and the names other sellers use.

Nothing ready in your size? Get batch alerts and Mike will email you when a new batch is ready.