The Short Answer
To set the right portions, start with your vet's recommended daily calorie intake, divide by the number of meals, and convert to grams using the calorie density on your food packaging. Then verify with your feeder's actual dispense amount by measuring a test serving into a kitchen scale.
This is where most pet owners go wrong. They trust the serving suggestion on the pet food bag — which is almost always too high, since pet food companies profit when you buy more food. Accurate portioning starts with your vet, not the back of the bag. While you're setting things up, take a look at our automatic feeders with precision dispensing for models with the most consistent portion accuracy we've tested.
Step 1: Get the Right Daily Calorie Target
Your vet can calculate your pet's Resting Energy Requirement (RER) and adjust it based on activity level, age, neuter status, and health goals. For a general starting point:
- Average adult indoor cat: 180–250 calories/day
- Average adult small dog (under 10 kg): 250–400 calories/day
- Average adult medium dog (10–25 kg): 400–700 calories/day
These are rough ranges. Your specific pet may need more or less. Always confirm with your vet if your pet is overweight, underweight, or on a prescription diet.
Step 2: Convert Calories to Grams
Find the caloric density on your pet food packaging. It's usually listed as kcal/kg or kcal per cup. Divide your pet's daily calorie target by the food's calorie density to get the daily gram amount.
Example: A cat needing 200 calories/day on food with 350 kcal/100g needs approximately 57g of food per day. Split across three meals, that's 19g per meal.
Step 3: Test Your Feeder's Actual Dispense Amount
This step is non-negotiable. Different kibble sizes and shapes affect how much actually comes out per "portion" setting on your feeder. What the feeder labels as "portion 3" might deliver 15g of one kibble and 22g of another.
Run the feeder's dispense function over a kitchen scale — zero the bowl first — and record the actual weight per setting. Do this 3 times and average the results. Then select the setting that matches your target gram amount as closely as possible.
Step 4: Monitor and Adjust Over 2 Weeks
Weigh your pet once a week for the first two weeks after switching to scheduled automatic feeding. You're looking for:
- Stable weight: Keep current settings
- Weight gain: Reduce each meal by 5–10%
- Weight loss (unintended): Increase each meal slightly and consult your vet
- Persistent begging or food anxiety: Consider splitting the same daily amount into more, smaller meals
Common Portioning Mistakes
Trusting the Bag Recommendations
Serving sizes on pet food packaging are guidelines for unspayed/unneutered, moderately active animals. Most indoor, neutered pets need 20–30% less. Use them only as an upper ceiling starting point, not a target.
Not Accounting for Treats
Treats count as calories. If you give treats during training or enrichment, subtract that caloric equivalent from the feeder portion. Vets typically recommend treats account for no more than 10% of daily calorie intake.
Setting Too Many Meals at Once and Forgetting
If you set your feeder and stop paying attention, portion drift goes unnoticed. Set a monthly phone reminder to weigh your pet and do a feeder calibration check. Kibble size can change between bags — same brand, slightly different dispense weight.
The Precision Advantage
A well-calibrated automatic feeder is more consistent than even the most careful human hand-feeding. Every meal, same weight, same time. For pets on weight management programs, that consistency is measurably better than guessing by eye twice a day. It takes 20 minutes to set up correctly. After that, it runs itself.
