PawsMathHow this dog food calculator works
Veterinary nutritionists estimate a dog’s energy needs in two steps:
-
Resting Energy Requirement (RER): the calories needed just to keep the body running at rest:
RER = 70 × (body weight in kg)0.75 - Maintenance Energy Requirement (MER): RER multiplied by a factor for life stage and activity. A typical neutered pet dog uses 1.6, a growing puppy 2–3 and a working dog 3–5 or more.
The result is then divided by the calorie density of your food to give cups per day. Not sure whether your dog counts as a senior yet? Our dog age calculator shows the life stage for your dog’s size.
Daily calorie guide by weight
Approximate calories for a healthy, neutered adult dog (factor 1.6):
| Weight | kcal / day | Cups / day (350 kcal/cup) |
|---|---|---|
| 5 lb (2.3 kg) | 210 | 0.6 |
| 10 lb (4.5 kg) | 350 | 1.0 |
| 20 lb (9.1 kg) | 590 | 1.7 |
| 30 lb (13.6 kg) | 790 | 2.3 |
| 40 lb (18.1 kg) | 980 | 2.8 |
| 50 lb (22.7 kg) | 1160 | 3.3 |
| 60 lb (27.2 kg) | 1330 | 3.8 |
| 70 lb (31.8 kg) | 1500 | 4.3 |
| 80 lb (36.3 kg) | 1660 | 4.7 |
| 100 lb (45.4 kg) | 1960 | 5.6 |
Tips for feeding the right amount
- Weigh, don’t guess. A kitchen scale is more accurate than a cup. If your bag lists kcal/kg, divide daily kcal by that number and multiply by 1,000 for grams.
- Check body condition monthly. You should feel the ribs easily under a thin layer of fat and see a waist from above. See our body condition score guide.
- Adjust in 10% steps. If your dog gains weight, cut portions by 10% and recheck in 2–4 weeks.
- Use ideal weight for overweight dogs. Feeding for current weight keeps an overweight dog overweight. Use the dog weight loss calculator instead.
- Pregnant and nursing dogs need much more food, up to 2–4 times maintenance during peak lactation. Feed a puppy or performance food and follow your vet’s plan.
- Feeding raw? Raw diets are usually portioned by body weight rather than by cups. The raw dog food calculator does that math.
- Don’t forget water. Kibble is only about 10% moisture, so dry-fed dogs drink more. Here’s how much water is normal.
Common questions
How many cups of food should my dog eat a day?
It depends on the calories in your food. Divide your dog’s daily calorie need (from the calculator) by the "kcal per cup" printed on the bag. A 50 lb neutered adult needs about 1,100–1,200 kcal, which is around 3.2 cups of a 350 kcal/cup kibble.
Where do I find kcal per cup?
Pet foods sold in the US must list calorie content on the label, usually near the guaranteed analysis as "kcal/kg" and "kcal/cup". Wet food lists "kcal/can". Use a standard 8 oz measuring cup, not a mug or scoop.
Should I feed according to the bag or this calculator?
Both are starting points. Bag charts are usually generous because they cover active, intact dogs. Start with the calculator, weigh your dog every 2–4 weeks and adjust by about 10% until weight is stable and body condition is ideal.
How many meals a day should a dog have?
Puppies under 6 months usually eat 3–4 meals a day. Most adult dogs do well on 2 meals. Deep-chested large breeds may benefit from 2–3 smaller meals to reduce bloat risk.
Do treats count toward daily calories?
Yes. Keep treats and chews under 10% of daily calories and reduce meals slightly if you give a lot. Our dog treat calculator shows exactly how much room you have.
Sources
- Global Nutrition Guidelines, World Small Animal Veterinary Association
- Nutritional Requirements of Small Animals, Merck Veterinary Manual
A calculator can't examine your dog. If anything seems off, or you're unsure, your veterinarian is the right person to ask. Disclaimer