The maths, with your numbers
No guesswork and no brand chart. This is the same calculation a vet does on paper, so you can check it.
What this means for the bowl
Purina ONE +Plus Healthy Weight High-Protein is on the lighter side: at 326 kcal per cup it has less energy than 91% of the 140 dry dog foods in our list, so the bowl will look fuller for the same calories.
To show how much the food matters: a 40 lb spayed or neutered dog needs about 985 kcal a day. That is 3 cups of this food, but 1 ⅞ cups of Purina Pro Plan All Ages Sport Performance 30/20 Salmon & Rice and 3 ⅝ cups of Kirkland Signature Healthy Weight Chicken and Vegetable. Same dog, same day, very different scoops.
This is a weight-control recipe. If your dog needs to slim down, tick “Needs to lose weight” in the calculator and enter the target weight your vet gave you; the portion is then worked out for the target, not the current weight.
Purina ONE +Plus Healthy Weight High-Protein feeding chart
Daily amounts for healthy adult dogs with no treats, from the label calories and the AAHA 2021 energy factors. Split the amount into meals.
| Weight | Couch dog | Spayed or neutered | Very active |
|---|---|---|---|
| 5 lb 2.3 kg | ½ cup | ⅝ cup | ¾ cup |
| 10 lb 4.5 kg | ¾ cup | 1 ⅛ cups | 1 ⅜ cups |
| 15 lb 6.8 kg | 1 ⅛ cups | 1 ½ cups | 1 ¾ cups |
| 20 lb 9.1 kg | 1 ⅜ cups | 1 ¾ cups | 2 ¼ cups |
| 30 lb 13.6 kg | 1 ⅞ cups | 2 ⅜ cups | 3 cups |
| 40 lb 18.1 kg | 2 ¼ cups | 3 cups | 3 ¾ cups |
| 50 lb 22.7 kg | 2 ⅝ cups | 3 ⅝ cups | 4 ½ cups |
| 60 lb 27.2 kg | 3 ⅛ cups | 4 ⅛ cups | 5 ⅛ cups |
| 70 lb 31.8 kg | 3 ½ cups | 4 ⅝ cups | 5 ¾ cups |
| 80 lb 36.3 kg | 3 ¾ cups | 5 ⅛ cups | 6 ⅜ cups |
| 90 lb 40.8 kg | 4 ⅛ cups | 5 ½ cups | 6 ⅞ cups |
| 100 lb 45.4 kg | 4 ½ cups | 6 cups | 7 ½ cups |
Label values: 326 kcal per cup. Source: purina.com, checked 18 Oct 2026.
Questions
How much Purina ONE +Plus Healthy Weight High-Protein should I feed a 50 lb dog?
About 3 ⅝ cups a day for a spayed or neutered dog, before treats. That is 1,164 kcal a day divided by the food’s label value. Use the calculator above to adjust for your pet.
How many calories are in Purina ONE +Plus Healthy Weight High-Protein?
The label states 326 kcal per cup (checked 18 Oct 2026). Recipes change, so check your bag.
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