The two-step formula, worked out
Step 1 is resting energy requirement: RER equals 70 times body weight in kilograms raised to the power of 0.75. Step 2 is maintenance energy requirement: multiply RER by a factor for your dog's life stage. For a typical spayed or neutered adult, the factor is 1.6. For an intact adult it is 1.8. For a senior over 7 years it is about 1.3. For a weight-loss plan, use 1.0.
Worked example: a 50 lb adult dog, neutered. Convert to kilograms: 50 times 0.4536 is 22.68 kg. RER is 70 times 22.68 to the power of 0.75, which is about 727 calories. Multiply by 1.6: about 1,164 calories per day. At 350 kcal per cup, that is 1,164 divided by 350, or 3.33 cups per day. Split into 2 meals: about 1.7 cups per meal.
Second example: a 22 lb dog, the same size as the calculator's default. In kilograms that is 9.98 kg, RER about 393 calories. Times 1.6 gives about 629 calories per day, or 1.8 cups of a 350 kcal-per-cup food. The 0.75 exponent is why portions do not scale straight with weight: the 50 lb dog is about 2.3 times heavier than the 22 lb dog but needs only about 1.85 times the calories.
Daily feeding chart by weight
Calories per day and cups per day for spayed or neutered adults at two common food densities. For intact adults, multiply the calorie column by 1.125 (that is, 1.8 divided by 1.6). For seniors, multiply by 0.81 (1.3 divided by 1.6).
| Dog weight | Calories per day | Cups per day at 350 kcal per cup | Cups per day at 400 kcal per cup |
|---|---|---|---|
| 5 lb | 207 | 0.59 | 0.52 |
| 10 lb | 348 | 0.99 | 0.87 |
| 15 lb | 472 | 1.35 | 1.18 |
| 20 lb | 585 | 1.67 | 1.46 |
| 30 lb | 794 | 2.27 | 1.99 |
| 40 lb | 985 | 2.81 | 2.46 |
| 50 lb | 1164 | 3.33 | 2.91 |
| 60 lb | 1335 | 3.81 | 3.34 |
| 80 lb | 1656 | 4.73 | 4.14 |
| 100 lb | 1958 | 5.59 | 4.90 |
A 400 kcal-per-cup food is noticeably denser, and you can see the difference in the last column: the 100 lb dog drops from 5.6 cups to 4.9 cups. Energy density matters more than most owners realize, which is why "cups" is a poor unit across brands.
Feeding for weight loss
More than half of US dogs are overweight. For a planned weight loss, use an MER factor of 1.0 times RER instead of 1.6. That is a reduction of about 37.5 percent from the maintenance amount, which produces slow, safe loss of roughly 1 to 2 percent of body weight per week.
The math: the 50 lb dog from the example has an RER of 727 calories, so the weight-loss target is 727 calories per day instead of 1,164. At 350 kcal per cup that is about 2.1 cups. Reweigh every 2 weeks. If weight is not dropping after a month, the usual culprit is treats, not the meals. Measure treats for one week and you will often find the missing 200 calories.
The 2-week adjustment rule
The formula gives you a precise starting point, not a final answer. Every dog's metabolism differs. After setting portions, weigh your dog (or weigh yourself holding the dog, then subtract) and wait 2 weeks. Gaining when you want steady? Cut 10 percent. Losing when you want steady? Add 10 percent.
Also score body condition, not just the scale. Run your hands over the ribs: you should feel them with light pressure but not see them. From above, look for a visible waist behind the ribs. From the side, the belly should tuck up behind the chest. A dog can be at a "fine" weight on the scale but carrying too little muscle, so condition plus weight together tell the real story.
Treats, table scraps, and the 10 percent rule
Treats count toward the daily total. The standard guidance: treats and extras should stay under 10 percent of daily calories. For the 50 lb dog at 1,164 calories, that is about 116 calories of treats per day, roughly 5 or 6 small training treats.
Training weeks are the danger zone. Fifty small treats in a training session can add 200 to 300 calories, silently erasing a careful meal plan. Options: subtract the treat calories from the next meal, use part of the daily kibble as training rewards, or switch to low-calorie treats. Dental chews count too, and many carry 50 to 100 calories each, so read their labels.