RER vs MER: the two numbers that matter
RER (resting energy requirement) is the energy a dog uses at rest for basic body functions: RER = 70 × kg0.75. MER (maintenance energy requirement) adjusts RER for real life: neutered adults usually need about 1.6 × RER, intact adults 1.8 ×, and inactive or weight-prone dogs closer to 1.2-1.4 ×.
Daily calories by dog weight
| Weight | RER | Neutered adult (×1.6) | Inactive (×1.2) | Active (×2.0) |
|---|---|---|---|---|
| 5 lb | 129 kcal | 207 kcal | 155 kcal | 259 kcal |
| 10 lb | 218 kcal | 348 kcal | 261 kcal | 435 kcal |
| 15 lb | 295 kcal | 472 kcal | 354 kcal | 590 kcal |
| 20 lb | 366 kcal | 585 kcal | 439 kcal | 732 kcal |
| 30 lb | 496 kcal | 794 kcal | 595 kcal | 992 kcal |
| 40 lb | 615 kcal | 985 kcal | 738 kcal | 1,231 kcal |
| 50 lb | 727 kcal | 1,164 kcal | 873 kcal | 1,455 kcal |
| 60 lb | 834 kcal | 1,335 kcal | 1,001 kcal | 1,668 kcal |
| 70 lb | 936 kcal | 1,498 kcal | 1,124 kcal | 1,873 kcal |
| 80 lb | 1,035 kcal | 1,656 kcal | 1,242 kcal | 2,070 kcal |
| 90 lb | 1,131 kcal | 1,809 kcal | 1,357 kcal | 2,261 kcal |
| 100 lb | 1,223 kcal | 1,958 kcal | 1,468 kcal | 2,447 kcal |
| 120 lb | 1,403 kcal | 2,244 kcal | 1,683 kcal | 2,806 kcal |
How vets calculate weight-loss calories
A common veterinary approach is to feed 1.0 × RER at the dog's ideal weight. Because RER is calculated on the lower target weight, this creates a steady calorie deficit. A safe rate of loss for dogs is about 1-2% of body weight per week. Faster loss risks muscle loss and hunger-driven behavior problems.
- Ask your vet to estimate an ideal weight using body condition scoring.
- Calculate RER at the ideal weight and feed that amount, including treats.
- Weigh every 2-4 weeks. If loss stalls, your vet may reduce calories by another 5-10%.
- Use a weight-management diet so your dog still gets enough protein, vitamins and minerals while eating fewer calories.
Low-calorie treat swaps
Swapping biscuits for low-calorie foods is one of the easiest ways to cut calories. Good options include green beans, cucumber, baby carrots and blueberries. Each of our food pages calculates how many pieces fit your dog's daily treat budget.
Frequently asked questions
How many calories should a dog eat per day?
A typical neutered adult needs roughly 1.6 × RER. For example, a 20 lb dog needs about 585 kcal per day and a 60 lb dog about 1,335 kcal per day. Activity, age and metabolism vary.
How many calories should a dog eat to lose weight?
Vets often start at 1.0 × RER calculated at the ideal weight. For a dog whose ideal weight is 50 lb, that is about 727 kcal per day.
How fast should my dog lose weight?
About 1-2% of body weight per week is considered safe. A 70 lb dog would lose roughly 0.7-1.4 lb per week.
Do treats count toward calories?
Yes. All treats, chews and table scraps count. Keep them under 10% of the daily total.