The puppy formula: RER times the growth factor
Resting energy requirement, RER, is 70 times body weight in kilograms raised to the power of 0.75. For a puppy you multiply RER by a growth factor instead of the adult maintenance factor: 3.0 for puppies under 4 months old, 2.0 for puppies from 4 to 12 months. This is why puppy portions look generous next to adult portions. A growing body is building bone, muscle, and brain tissue around the clock.
Worked example: a 15 lb Labrador puppy at 3 months. Convert to kilograms: 15 times 0.4536 is 6.8 kg. RER is 70 times 6.8 to the power of 0.75, which is about 295 calories. Multiply by the 3.0 growth factor: 885 calories per day. A puppy kibble at 375 kcal per cup gives 885 divided by 375, which is 2.36 cups per day. Split into 3 meals: about 0.8 cups per meal.
Second example: the same puppy at 7 months, now 25 lb. In kilograms that is 11.34 kg, RER about 433 calories. The growth factor drops to 2.0, so daily calories are about 865. At 375 kcal per cup that is 2.31 cups per day, now in 2 meals: about 1.15 cups each. Notice the dog got much bigger but the daily total barely moved, because the growth factor fell. This is the pattern to expect as puppies age.
Puppy feeding chart by weight
The table below gives daily calories and cups per day for typical puppies at two ages. It assumes a puppy food at 375 kcal per cup, which is a common energy density. If your food differs, divide the calorie number by your food's kcal per cup.
| Puppy weight | 2 to 4 months (factor 3.0): kcal per day | Cups per day | 4 to 12 months (factor 2.0): kcal per day | Cups per day |
|---|---|---|---|---|
| 5 lb | 388 | 1.03 | 259 | 0.69 |
| 10 lb | 653 | 1.74 | 435 | 1.16 |
| 15 lb | 885 | 2.36 | 590 | 1.57 |
| 20 lb | 1098 | 2.93 | 732 | 1.95 |
| 30 lb | 1488 | 3.97 | 992 | 2.65 |
| 40 lb | 1846 | 4.92 | 1231 | 3.28 |
| 50 lb | 2182 | 5.82 | 1455 | 3.88 |
These are starting points, not prescriptions. An active breed mix at the dog park five days a week runs hotter than a quieter puppy of the same weight. Reweigh every two weeks during growth spurts and adjust by 10 percent at a time.
Three meals, then two: the puppy schedule
Under about 6 months, feed 3 meals a day. Tiny breeds under 12 weeks sometimes need 4 small meals to keep blood sugar steady. Around 6 months, most puppies transition to 2 meals a day, which most adult dogs keep for life.
Consistent timing matters as much as the amount. Feed at roughly the same hours each day, give 20 to 30 minutes to eat, then pick up what is uneaten. Predictable meals make house training far easier, because what goes in on a schedule comes out on a schedule. Leave water available all day, but many owners pick it up about two hours before bed during crate training.
When puppies switch to adult food
Puppy food has more protein, fat, calcium, and phosphorus than adult food, which growing bones need. Switch too early and you shortchange growth; switch too late and a finished growing dog gets excess calories. Rough guides: small breeds at 9 to 12 months, medium breeds at about 12 months, large and giant breeds at 12 to 18 months, since they keep growing longer.
Transition over 7 to 10 days. Start with 25 percent new food mixed with 75 percent old, move to half and half, then 75/25, then full new food. An abrupt switch is the most common cause of the digestive upset owners blame on the new food itself. During the transition, watch stool quality: it is the fastest feedback your puppy gives you.
Overfeeding signs and how to adjust
Puppies should be lean. Run your hands along the ribs with light pressure: you should feel them easily without seeing them. From above, you should see a slight waist behind the ribs. A round belly, ribs you cannot find, and very rapid weight gain are signs to cut back.
Soft stools are another signal. Many puppies get loose stools when fed too much, and owners switch foods when the fix is simply a smaller portion. If stools are soft, reduce by 10 percent and wait three days before changing anything else. When in doubt, ask your veterinarian at the next vaccine visit: they see the growth curve across hundreds of puppies and can tell you in seconds whether your puppy is on track.