How the numbers are worked out, what to do with them, and reference tables for common sizes.
How to use the calculator
There are five inputs. Each one changes the result:
Weight (pounds). Use a recent, real weight. If your dog is overweight, use the target weight your vet recommends, otherwise the result will maintain the extra weight.
Breed (optional). Choosing a breed sets the size class, which applies a small adjustment: toy and small dogs burn slightly more per kilogram than large and giant dogs. With no breed, the size class comes from weight.
Life stage. Puppies under 6 months use the highest multiplier, puppies 6–12 months a lower one, adults a standard one, and seniors (7 and older) the lowest. Pick the stage that matches your dog today.
Spayed or neutered. Neutered dogs usually need somewhat fewer calories than intact dogs.
Activity. Low is mostly indoors with short walks, moderate is daily walks, and high is regular runs, hikes or work. Most owners overestimate, so if you are unsure choose moderate.
The cup and gram amounts assume dry food at 350 kcal per cup and 120 g per cup. Check your own food's label: if it lists, say, 420 kcal per cup, multiply the cups shown by 350 and divide by 420.
What the results mean
RER (resting energy requirement) is the energy a dog uses at rest: 70 × (body weight in kg)0.75. A 20 kg dog has an RER of about 660 kcal.
Daily calories are the RER multiplied by factors for life stage, neuter status, activity and size. A neutered adult at moderate activity uses about 1.6 × RER; an intact adult about 1.8 ×; a puppy under 6 months about 3 ×.
Daily portion is those calories divided by the food's calories per cup, split across the suggested number of meals.
Your bag's feeding guide may differ. Bag guides are written for an average dog and cannot account for neuter status or how active your dog is. Many dogs do well on a little less than the bag suggests, but use body condition to decide.
Adjust to your dog. Treat the result as a starting point. Weigh your dog and check body condition every few weeks. If you cannot feel the ribs, trim portions by about 10%. If the ribs and hip bones are prominent, increase by about 10%. Change in small steps and recheck.
This is general feeding information for healthy dogs, not veterinary advice. Ask your vet before changing the diet of a puppy with a growth problem, a senior dog, or any dog with a medical condition. For more on choosing food, see our dry dog food label guide.
Daily calories by weight
These tables use the same formula as the calculator with no breed selected and moderate activity unless stated, rounded to the nearest 5 kcal. They are estimates for healthy dogs. Use the calculator for your own dog, and your vet's advice if your dog has special needs.
Examples: Labrador Retriever, Golden Retriever, German Shepherd, Boxer
Weight
Neutered adult
Intact adult
Neutered, high activity
Puppy (6–12 mo)
Senior (neutered)
30 kg / 66 lb
1,365 kcal
1,535 kcal
1,635 kcal
2,130 kcal
1,195 kcal
35 kg / 77 lb
1,530 kcal
1,720 kcal
1,835 kcal
2,390 kcal
1,340 kcal
40 kg / 88 lb
1,690 kcal
1,905 kcal
2,030 kcal
2,645 kcal
1,480 kcal
45 kg / 99 lb
1,750 kcal
1,970 kcal
2,100 kcal
2,735 kcal
1,530 kcal
Large-breed puppies should eat a food made for large-breed growth and stay lean, because growing too fast can strain developing joints.
Giant dogs (over about 45 kg / 100 lb)
Examples: Great Dane, Saint Bernard, Newfoundland, Mastiff
Weight
Neutered adult
Intact adult
Neutered, high activity
Senior (neutered)
50 kg / 110 lb
1,895 kcal
2,130 kcal
2,275 kcal
1,660 kcal
60 kg / 132 lb
2,175 kcal
2,445 kcal
2,610 kcal
1,900 kcal
70 kg / 154 lb
2,440 kcal
2,745 kcal
2,925 kcal
2,135 kcal
80 kg / 176 lb
2,695 kcal
3,035 kcal
3,235 kcal
2,360 kcal
Giant breeds reach their senior years earlier. Ask your vet about the right diet for a giant-breed puppy.
How much food is 900 kcal?
Typical values only. Use the kcal on your food's label.
Food type
Typical energy
Approx. amount for 900 kcal
Dry kibble (standard)
320–380 kcal/cup
2.4–2.8 cups
Dry kibble (high density)
400–450 kcal/cup
2.0–2.25 cups
Wet food (canned)
80–100 kcal/100g
900–1,125g
Raw (BARF)
120–180 kcal/100g
500–750g
Homemade (mixed)
Varies widely
Use kcal count from recipe
Frequently asked
Dog feeding questions
It uses the same RER × DER formulas vets use. The math is exact; the inputs are estimates. For most healthy adult dogs, you should be within ±10% of true requirements — well within normal variation.
Dog food calculator for wet and dry food
When you mix wet and dry food, split the calories, not the cups. For example, if your dog needs 900 kcal a day and you want one can of wet food (say 400 kcal), feed the remaining 500 kcal as kibble. Use the kcal per can and kcal per cup printed on each label.
Dog food calculator in grams
Grams are more accurate than cups. Divide your dog's daily calories by the food's kcal per kg, then multiply by 1,000. Example: 900 kcal ÷ 3,600 kcal/kg × 1,000 = 250 g a day.
Dog food calculator for weight loss and puppies
Weight loss: vets usually start from the resting energy requirement (RER) at the dog's target weight, then adjust every 2–4 weeks. Aim for about 1–2% of body weight lost per week. See how to calculate dog calories for weight loss.
Puppies: puppies need about 3 × RER up to 4 months old and about 2 × RER after that until they are grown. Use the puppy feeding chart.
How we calculate
The math, openly documented.
01
Inputs
Weight, breed, life stage, activity, neuter status — only what changes the math.
weight = 42 lbs
activity = "moderate"
02
Resting (RER)
NRC formula for resting calorie burn.
RER = 70 × (kg^0.75)
≈ 633 kcal
03
Daily (DER)
RER × activity and life-stage factor.
DER = RER × factor
≈ daily kcal
04
Output
Convert to cups, grams, and meal split.
cups ≈ DER ÷ kcal/cup
meals = 2 × g/2
Safety check
What to never feed your dog
Even tiny amounts can be fatal. If your dog ingested any of these, call your vet or the ASPCA poison line (888-426-4435) immediately.
