Nutrient Constraint Calculator
Track if the food you're giving your rabbits is within safe nutritional limits. Like MyFitnessPal for rabbits - add foods and monitor 27 different nutrients in real-time.
Track if the food you're giving your rabbits is within safe nutritional limits. Like MyFitnessPal for rabbits - add foods and monitor 27 different nutrients in real-time.
No foods added yet
The main goal for a pet rabbit's diet is to limit the chances of developing digestive problems, which is the most common cause of health issues in pet rabbits.
Romaine Lettuce, Cilantro, Parsley, Bok Choy, Carrot Tops, Dandelion Greens, Watercress, Basil, Mint, Endive, Escarole, Fennel, Wheatgrass
Kale, Spinach, Beet Greens, Broccoli (leaves), Carrots, Bell Peppers, Zucchini, Celery
Iceberg Lettuce, Potatoes, Corn, Beans, Rhubarb, Onions, Garlic
Timothy Hay, Orchard Grass, Meadow Hay, Oat Hay, Botanical Hay
Alfalfa Hay (high in calcium, suitable for rabbits under 6 months)
Apple (no seeds), Banana, Strawberry, Blueberry, Raspberry, Papaya, Pear, Peach, Melon, Pineapple
Chocolate, Candy, Cookies, Bread, Pasta, Cereal, Nuts, Seeds, Yogurt Drops
This rabbit nutrient constraint calculator works like MyFitnessPal for rabbits. Enter your rabbit's weight, select a food from the database of 60+ items, set the amount in grams, and click "Add Food." The calculator tracks 27 nutrients in real-time, showing you exactly where each nutrient falls relative to safe limits.
Progress bars turn green when a nutrient is within the safe range, yellow when approaching the upper limit, and red when it exceeds the maximum. All limits automatically scale based on your rabbit's body weight, so a 1 kg dwarf rabbit has different thresholds than a 5 kg Flemish Giant.
Add multiple foods to see cumulative totals. This is especially useful for checking whether a combination of vegetables exceeds the calcium limit, or whether your pellet and hay combination provides enough fiber. Use the reset button to start over with a new food combination.
Rabbits have specific nutritional requirements that differ significantly from dogs, cats, and even other herbivores like guinea pigs. Here are the key nutrients and their roles in rabbit health:
| Nutrient | Safe Range | Primary Role | Best Sources |
|---|---|---|---|
| Crude Fiber | 14-20% | Gut motility, dental wear, cecal fermentation | Timothy hay, orchard grass, oat hay |
| Protein | 12-16% | Muscle maintenance, growth, fur production | Pellets, alfalfa hay (young rabbits), leafy greens |
| Fat | 1-3% | Energy, fat-soluble vitamin absorption | Pellets, seeds in hay (minimal) |
| Calcium | 0.5-1.0% | Bone density, teeth, muscle function | Leafy greens, hay, pellets |
| Phosphorus | 0.4-0.8% | Bone structure, energy metabolism | Pellets, hay, vegetables |
| Vitamin A | 5,000-12,000 IU/kg | Vision, immune function, reproduction | Carrot tops, dandelion greens, kale |
The most critical nutrient for rabbits is fiber. Without adequate fiber from hay, the entire digestive system breaks down. Protein and fat should be moderate, as excess causes obesity and liver problems. Calcium must be carefully controlled in adults to prevent bladder sludge.
Calcium metabolism in rabbits is unique among mammals. Unlike dogs and cats, rabbits absorb all dietary calcium from the gut regardless of need. Excess calcium is excreted through the kidneys rather than regulated at the intestinal level. This means whatever calcium goes in must come out through urine, which is why rabbit urine is naturally cloudy and white.
The ideal Ca:P ratio for rabbits is 1.5:1 to 2:1. This means 1.5 to 2 parts calcium for every 1 part phosphorus. When this ratio is inverted (more phosphorus than calcium), rabbits develop metabolic bone disease. When calcium is too high relative to phosphorus, bladder sludge and kidney stones become a risk.
254 mg calcium per 100g. Excellent nutrition overall, but should be rotated with lower-calcium greens. Feed 2 to 3 times per week, not daily.
138 mg calcium per 100g. High in vitamin C and K. Good in moderation, limit to 2 to 3 times per week alongside lower-calcium staples.
187 mg calcium per 100g. Wild-foraged greens are nutritious but calcium-dense. Mix with romaine or cilantro to balance the ratio.
33 mg calcium per 100g. Low calcium, safe daily. This should be a diet staple for adult rabbits needing calcium control.
Rabbits are hindgut fermenters with a digestive system built around fiber. The cecum (a large pouch at the junction of the small and large intestine) ferments fiber into volatile fatty acids and B vitamins. This process only works when the rabbit eats enough long-strand fiber from hay.
| Fiber Type | What It Is | Ideal Range | What Happens if Too Low |
|---|---|---|---|
| Crude Fiber | Total indigestible plant material | 14-20% of diet | GI stasis, dental overgrowth |
| ADF (Acid Detergent Fiber) | Cellulose + lignin (indigestible fraction) | 17-22% of diet | Slow gut transit, soft stools |
| NDF (Neutral Detergent Fiber) | Total cell wall content (includes hemicellulose) | 30-35% of diet | Reduced cecal fermentation |
This calculator tracks all three fiber types because they measure different aspects of digestibility. ADF and NDF are the values used in commercial feed formulation, while crude fiber appears on most pellet labels. A diet high in timothy hay naturally meets all three fiber targets.
Nutritional problems in rabbits develop gradually and are often missed until they become serious. Here are the most common signs linked to specific nutrient imbalances:
| Symptom | Likely Cause | Fix |
|---|---|---|
| White, gritty urine or bladder sludge | Excess calcium | Switch from alfalfa to timothy hay, reduce kale/parsley/spinach |
| Soft, mushy cecotropes stuck to fur | Too much sugar/starch, not enough fiber | Cut treats and pellets, increase hay |
| Overgrown teeth, difficulty eating | Insufficient fiber (not enough hay chewing) | Unlimited hay, reduce pellets to encourage hay eating |
| Dull, thin coat or excessive shedding | Low protein or vitamin deficiency | Ensure adequate pellets and varied greens |
| Obesity, large dewlap fold | Excess pellets, treats, or starchy foods | Reduce pellets to 1/4 cup per 6 lbs, eliminate daily treats |
| Weight loss despite eating | Dental disease or malabsorption | Veterinary exam for dental check and bloodwork |
Fiber is the single most important nutrient. Rabbits need 14 to 20% crude fiber in their diet, primarily from unlimited hay. After fiber, controlled calcium (0.5 to 1.0%), moderate protein (12 to 16%), and low fat (1 to 3%) are the key targets. Vitamins A, D, and E must come from food, while B vitamins are produced through cecal fermentation.
Adult rabbits need 5 to 10 grams of calcium per kilogram of body weight in their diet. Unlike other mammals, rabbits absorb all dietary calcium and excrete the excess through urine. Too much calcium causes bladder sludge and kidney stones. Rotate high-calcium greens like kale and parsley with low-calcium options like romaine and cilantro.
Rabbits are hindgut fermenters. Their entire digestive system depends on long-strand fiber from hay to drive gut motility and fuel cecal fermentation. Without enough fiber, the gut slows down and GI stasis develops, which is fatal without treatment. Protein is needed for growth and maintenance but does not drive the digestive system the way fiber does.
The ideal ratio is 1.5:1 to 2:1 (calcium to phosphorus). This means about 1.5 to 2 times more calcium than phosphorus. An inverted ratio causes metabolic bone disease, while excessive calcium leads to urinary problems. Most balanced rabbit diets naturally achieve this ratio when hay is the primary food source.
Yes. Fat-soluble vitamins (A, D, E) accumulate in the body and can reach toxic levels. Vitamin A toxicity causes liver damage and bone problems. Vitamin D excess leads to calcium deposits in soft tissues. Water-soluble B vitamins are less risky because excess is excreted, but balance still matters. Avoid vitamin supplements unless prescribed by a veterinarian.
A balanced diet produces firm, round fecal pellets, healthy cecotropes that the rabbit eats, a shiny coat, stable weight, and clear (slightly cloudy) urine. Use this nutrient calculator to check specific food combinations against safe limits. The simplest approach is the 80/10/9/1 rule: 80% hay, 10% vegetables, 9% pellets, 1% treats.