Small Mammal Nutrition

Determine the ideal diet portions for small mammals. Calculate hay, pellet, and vegetable amounts for rabbits, guinea pigs, and hamsters.

Calculate daily food requirements for rabbits, guinea pigs, and hamsters.

About This Calculator

Provide the perfect diet for your pocket pet with the Small Mammal Nutrition Calculator. Rabbits, guinea pigs, and hamsters have highly specialized digestive systems that differ significantly from dogs and cats. Just as humans benefit from tracking their macronutrient intake, these small herbivores and omnivores require a precise balance of fiber, fresh vegetables, and limited pellets.

The foundation of rabbit and guinea pig health is unlimited Timothy hay, which provides essential fiber for gut motility and wears down their continuously growing teeth. Without adequate fiber, these animals can develop life-threatening conditions like GI stasis. Hamsters, as omnivores, have different needs—requiring a balanced mix of grains, seeds, and occasional protein.

One critical difference: guinea pigs cannot synthesize their own Vitamin C (just like humans!), making them susceptible to scurvy. They require 10-30mg of Vitamin C daily from fortified pellets and fresh vegetables like bell peppers and parsley.

Daily Feeding Guidelines

Rabbit: Hay (unlimited) + 1/4 cup pellets per 4-5 lbs + 1 cup veggies per 4 lbs

Guinea Pig: Hay (unlimited) + 1/8 cup pellets + 1 cup veggies + Vitamin C

Hamster: 1-2 tbsp seed mix + tiny veggie treats

Species Diet Reference

Species	Primary Diet	Hay Requirement	Special Notes
Rabbit	Herbivore	80% of diet	Limit pellets; avoid high-sugar treats
Guinea Pig	Herbivore	80% of diet	Requires Vitamin C supplementation
Hamster	Omnivore	Bedding only	Needs protein; can eat insects

Practical Example

For a 5 lb rabbit: Provide unlimited Timothy hay (should eat a body-sized pile daily), 1/4 cup plain pellets, 1.25 cups mixed leafy greens (romaine, cilantro, parsley), and fresh water. Limit fruit to 1-2 tablespoons as occasional treats.

Safe Vegetables by Species

Rabbits: Romaine, cilantro, parsley, basil, bok choy (avoid iceberg lettuce)
Guinea Pigs: Bell peppers (high Vitamin C!), cucumber, tomato, leafy greens
Hamsters: Carrots, broccoli, cucumber (tiny amounts only)

Feeding Tips

Always provide fresh, clean water in a bottle or heavy bowl
Introduce new vegetables gradually to avoid digestive upset
Remove uneaten fresh food after 24 hours to prevent spoilage
Store pellets in airtight containers to preserve Vitamin C

Scenario Comparison: Daily Food Requirements

Species	Weight	Pellets	Fresh Veggies
Adult Rabbit (4 lbs)	1.8 kg	1/4 cup	1 cup leafy greens
Large Rabbit (10 lbs)	4.5 kg	1/2 cup	2.5 cups leafy greens
Guinea Pig (2 lbs)	0.9 kg	1/8 cup	1 cup + Vitamin C source
Syrian Hamster	120-150g	1-2 tbsp mix	Tiny pieces (treats only)

All species require unlimited Timothy hay except hamsters.

Common Small Mammal Feeding Mistakes to Avoid

Overfeeding pellets, underfeeding hay: Hay should be 80%+ of rabbit/guinea pig diet. Too many pellets causes obesity and dental disease.
Forgetting guinea pig Vitamin C: Unlike rabbits, guinea pigs cannot synthesize Vitamin C. Deficiency causes scurvy within 2-3 weeks.
Feeding lettuce as primary veggie: Iceberg lettuce is mostly water with no nutrition. Use romaine, cilantro, or bell peppers instead.
Giving hamsters wet-tail causing foods: Too many fresh vegetables cause diarrhea. Limit to tiny pieces 2-3x weekly.

Small Mammal Nutrition Benchmarks

Nutrient	Rabbit	Guinea Pig	Hamster
Fiber requirement	18-25%	15-20%	6-15%
Protein	12-14%	14-16%	15-18%
Fat	2-4%	3-4%	4-7%
Vitamin C (daily)	Synthesizes own	10-30 mg	Synthesizes own

When to Use This Calculator vs Others

This calculator: Best for rabbits, guinea pigs, and hamsters to determine hay, pellet, and veggie portions.
Pet Meal Calculator: Use for dogs and cats—their nutritional needs are completely different.
Exotic Pet Nutrition: Use for ferrets, hedgehogs, and sugar gliders which have carnivore/insectivore diets.
Bird Nutrition Calculator: Use for parrots, canaries, and other pet birds.

Related tools: Pet Meal Calculator for dogs and cats, Exotic Pet Nutrition for ferrets and hedgehogs, and Bird Nutrition Calculator for feathered friends.

Frequently Asked Questions

How is small mammal food amount calculated?

Rabbits: 1/4 cup pellets per 5 lbs + 1 cup veggies per 4 lbs + unlimited hay. Guinea pigs: 1/8 cup pellets + 1 cup veggies. Hamsters: 1-2 tbsp mix.

How much hay should a rabbit eat?

Unlimited Timothy hay—should be 80% of diet. A rabbit should eat a pile of hay roughly its own body size daily. Essential for digestion and teeth.

Do guinea pigs need vitamin C supplements?

Yes! Guinea pigs can't make vitamin C (like humans). Need 10-30mg daily from bell peppers, leafy greens, or fortified pellets. Deficiency causes scurvy.