Dog Food Calculator: How Much to Feed a Dog by Weight

1. The calculator first estimates resting energy requirement with the formula RER = 70 x body weight in kilograms raised to the power of 0.75.
2. It then applies practical daily multipliers for life stage and activity so that puppies, active adults, seniors, and lower-activity dogs are not treated the same.
3. A cautious body-condition adjustment is then applied for underweight or overweight adult dogs, while puppy results avoid weight-loss advice.
4. Finally, the calorie range is converted into grams per day, cups per day, cans per day, and an estimated portion per meal based on the label format you enter.

• Metric mode is the default here because many UK labels use kilocalories per 100 grams, but you can still switch to pounds and cups if that matches the food label you have.
• Pick the life stage that best matches your dog now because calorie needs can shift meaningfully across growth, adulthood, and the senior years.
• Use body condition honestly. A dog that is visibly overweight may need a lower target than a dog at an ideal condition.
• Enter the number of meals you actually feed each day so the calculator can show an estimated portion per meal.

The daily calorie result is shown as a range rather than one fixed number because real dogs rarely need exactly the same energy intake every day.

Metric label mode gives grams per day and grams per meal, while US-style label mode still allows cups or cans if that is the only calorie statement available.

Treat the portion-per-meal output as a convenience estimate rather than a precise prescription.

• Look for the calorie statement near the feeding guide or analytical constituents. UK packaging often lists kilocalories per kilogram or per 100 grams.
• If the label provides only kilocalories per kilogram, convert it carefully or check the brand website for a clearer metric feeding reference.
• When the label gives kilocalories per 100 grams, metric mode is usually the cleanest option because the output stays in grams per day.

• Dry food usually looks smaller by volume because it is more calorie-dense, so cups per day can seem lower than expected.
• Wet food often needs more tins, trays, or pouches per day because it contains more moisture and fewer calories per ounce.
• A smaller dry-food volume can still contain more calories than a much larger wet-food serving.

• Recheck the label whenever you change brands because calorie density can differ substantially between recipes.
• Watch body condition over time instead of relying on the calculator alone. If your dog's shape, appetite, or stool quality changes, reassess.
• Treats and chews still add calories, so reduce meal portions if extras are a regular part of the routine.

• Mixing pounds with metric label mode or kilograms with cup-based label data.
• Using the serving suggestion on the pack instead of the actual calorie statement.
• Applying weight-loss thinking to puppies or rapid growth stages without veterinary guidance.

• Speak with your vet before making a major feeding change if your dog is pregnant, nursing, a giant-breed puppy, very old, underweight, overweight, or living with a medical condition.
• Veterinary input also matters if your dog gains weight despite portion control, loses weight unexpectedly, or develops digestive changes after a feeding adjustment.

• National Research Council. Nutrient Requirements of Dogs and Cats.
• WSAVA Global Nutrition Toolkit.
• AAHA Nutrition and Weight Management Guidance.