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The feeding guide on the bag is a range for “average” pets and often overfeeds indoor, neutered dogs and cats. This calculator uses the veterinary resting energy formula and life-stage factors to estimate your pet’s daily calories, then converts them into cups and grams using the energy content printed on your food.
How it works
Resting energy requirement (RER) = 70 × (body weight in kg)0.75. That’s the energy needed at rest. Daily needs are RER multiplied by a factor for life stage and activity:
| Dog | Factor | Cat | Factor |
|---|---|---|---|
| Adult, neutered | 1.6 | Adult, neutered | 1.2 |
| Adult, intact | 1.8 | Adult, intact | 1.4 |
| Inactive / senior | 1.2–1.4 | Inactive / weight-prone | 1.0 |
| Weight loss (ideal weight) | 1.0 | Weight loss (ideal weight) | 0.8 |
| Puppy under 4 months | 3.0 | Kitten | 2.5 |
| Puppy 4 months to adult | 2.0 | ||
| Light / moderate work | 2.0 / 3.0 |
These factors follow widely used veterinary nutrition guidance, including the WSAVA Global Nutrition Guidelines.
Where to find kcal per cup
US pet foods list “calorie content” on the bag, usually as kcal/kg and kcal per cup or can. Dry dog food typically ranges from 300 to 450 kcal per cup; dry cat food from 350 to 500.
FAQ
How do I know if I’m feeding the right amount?
Use body condition, not just the scale. You should be able to feel the ribs easily under a thin layer of fat and see a waist from above. Weigh every 2–4 weeks and adjust portions by about 10%.
Do treats count?
Yes — keep treats to 10% or less of daily calories and reduce meals to match if you train with food.
Is this suitable for weight loss?
It gives a reasonable starting point when you enter the target weight, but supervised weight loss with your vet is safer, especially for cats, which can develop liver problems if they lose weight too fast.
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