Free Online Dog Food Calculator

Wondering how much should I feed my dog calculator-style, without doing the maths yourself? This dog food calculator works out how much to feed a dog by weight (kg) or pounds, using your dog's activity level and your food's calories per cup. Use this dog feeding calculator to get a daily kcal target and a cups-per-day serving size in seconds.

Looking to calculate food portions for your feline friend? Head over to our Cat Food Calculator to easily estimate your cat’s daily calorie needs and meal size.

Dog Food Calculator

kcal / cup

Activity Level Reference

These are the daily-energy multipliers this calculator uses for each activity level, applied to your dog's metabolic weight.

Activity LevelMultiplier (K)
Overweight70
Senior, neutered, inactive90
Typical110
Active125
Working Dog (light duty)130–150
Working Dog (moderate duty)150–175
Highly Active175
Working Dog (heavy duty)175–250

Your Results

Your dog's daily calorie needs and recommended cups per day will appear here once you calculate.

How Much Should I Feed My Dog? The Formula Explained

Every dog burns energy differently depending on its size and lifestyle, so a flat "cups per day" chart on a food bag is only ever a rough starting point. A more accurate way to work out how much to feed a dog by weight (kg) is to calculate its daily energy requirement from its metabolic weight, then convert that energy figure into a serving size using your specific food's calorie content.

Step 1: Metabolic Weight

Larger dogs don't need proportionally as many calories as small dogs relative to their size, because bigger bodies are more efficient at converting food into energy. To account for this, veterinary nutritionists don't use raw body weight — they use metabolic weight, calculated as body weight in kilograms raised to the power of 0.75.

Metabolic weight = (Weight in kg) ^ 0.75

Step 2: Daily Energy Requirement

That metabolic weight is then multiplied by a factor for the dog's activity level, to get its total daily energy requirement in kilocalories:

Daily energy (kcal) = Activity Factor × Metabolic Weight

The activity factor ranges from as low as 70 for an overweight dog that needs to lose weight, up to 250 for a hard-working dog in heavy daily activity — see the full reference table alongside the calculator above.

Step 3: Converting Calories to Cups

Finally, divide the daily energy requirement by your specific food's calories per cup (usually printed on the bag as kcal/cup) to get the actual serving size:

Cups per day = Daily energy (kcal) ÷ Calories per cup

Worked Example

Say you have a 15kg dog with a Typical activity level (factor 110), fed a food with 350 kcal per cup:

Step 1: 150.75 = 7.62 (metabolic weight)
Step 2: 110 × 7.62 = 838 kcal/day
Step 3: 838 ÷ 350 = 2.39 cups/day

A Few Important Notes Before You Feed

  • This calculator is built for healthy adult dogs — not puppies, and not pregnant or nursing females, who all have very different nutritional needs.
  • The result assumes you feed the full daily amount in one sitting; if you split meals across the day, divide the total cups by the number of meals.
  • Treat the number as a starting point, not a fixed rule. Weigh your dog every few weeks and adjust the serving size up or down to keep them at a healthy weight.
  • If your dog has a medical condition, is on a prescription diet, or you're unsure about their ideal weight, check with your veterinarian before changing their feeding routine.

Frequently Asked Questions (FAQs)

No. This tool is designed for healthy adult dogs only. Puppies grow quickly and need a very different feeding schedule and calorie density, so always follow your puppy food's own feeding guide or your vet's advice instead.

Activity level is the single biggest driver of a dog's energy needs after body size. A working dog in heavy daily activity can need more than three times the calories of an overweight, sedentary dog of the same size, which is why the calculator's activity factor ranges from 70 up to 250.

Weigh out one cup of the food on a kitchen scale, then use the calories-per-kg figure to work out the calories in that exact cup weight. Enter that number into the calculator as the calories per cup.

Working dogs cover a wide spread of real-world effort, so the calculator gives a low-to-high range instead of a single figure. Start near the lower end and adjust upward if your dog is losing weight or condition during heavy work periods.

Roughly every 2 to 4 weeks, or any time your dog's weight, activity level, or food brand changes. Re-weigh your dog and re-run the calculator so the serving size keeps matching its current needs.
Disclaimer: This calculator provides a general estimate based on standard veterinary energy-requirement formulas and is not a substitute for advice from a licensed veterinarian. Every dog is different — use this figure as a starting point, monitor your dog's body condition regularly, and consult your vet for any health concerns or before making significant changes to their diet.