The ideal weight for a rabbit varies depending on breed and age. Your rabbit's spine, ribs, and hips should feel rounded with a light layer of padding. These areas should not feel sharp or bony (underweight), nor difficult to feel (overweight).
How to monitor your rabbit's weight
Fluctuations in weight can be a sign of improper diet or underlying health conditions. As prey animals, rabbits will try to hide signs of illness, making it difficult for their caregivers to detect changes.
Become familiar with how your rabbit looks and how their body feels. A monthly weigh in gives you a more precise way to detect changes when they start to occur.