Quick Answer
Browse guinea pig growth charts and weight ranges below. Use our breed-specific charts to track if your pet is on target.
📅
14 mo
Full size reached
⚖️
900-1200g
Avg Adult Weight
📝
Weekly
Weigh-in frequency
🐹
Males
Are 20-30% larger
📏Growth & Size Facts
Weigh Weekly
Buy a kitchen scale. Sudden weight loss is an emergency in guinea pigs.
Boars vs Sows
Males (boars) generally weigh 900-1200g, females (sows) 700-900g.
Rapid Start
Pups double their size in just a few weeks. Ensure access to alfalfa hay for calcium/protein.
Obesity Check
A guinea pig should have a rounded rump but shouldn't drag their belly on the ground.
Frequently Asked Questions
How big do guinea pigs get?
They typically reach 8-11 inches in length and weigh 1.5-2.6 lbs (700-1200g).
When are they fully grown?
They reach skeletal maturity around 8-9 months but may fill out until 14 months.
More Guinea Pig Resources
Track Your Pet's Growth
Create a free profile for your guinea pig to log weight checks, set reminders, and see personalized growth charts.
Start Tracking FreeTrusted sources: AKC Breed Standards · AVMA Pet Care