Dog Food Calculator
Daily cups and calories for your dog.
Starting estimate from published formulas. Your vet knows your pet.
How to use the dog food calculator
- Enter the dog's weight. Switch lb or kg if you need the other unit; the weight you typed is converted, not cleared.
- Choose puppy, adult or senior, then neutered or not, and a body shape. A puppy uses the age split instead of body shape.
- Type the kcal per cup printed on your food. The 350 that loads with the page is an example.
- Set meals per day if you want the day split. That number is your choice, not a required schedule.
- Read cups per day first, then the calories, the per-meal split and the treat line.
How the daily calories are worked out
Resting energy is the calories a fed dog uses at rest. Merck Veterinary Manual writes it as RER = 70 × (weight in kg)^0.75. A straight-line version exists only between 2 kg and 45 kg, and this page does not use it.
Daily calories, called maintenance energy or MER, are the resting figure multiplied by a factor from the same Merck table. An intact adult is 1.8. A neutered adult is 1.6. A dog described as obesity prone is 1.4. A puppy under 4 months is 3. A puppy over 4 months is 2. Exactly 4 months is not a row in the table, so the control asks you to pick under or over.
Body shape uses those adult rows rather than a new scale. Thin uses 1.8, the higher adult factor. Ideal uses 1.6 when the dog is neutered and 1.8 when not. Heavy uses 1.4, Merck's obesity-prone row. Senior is not a separate row. The page keeps the adult factor and says so.
Worked example for the numbers this page opens with
The page opens on a 20 lb neutered adult in ideal shape, with 350 kcal/cup and 2 meals. The factor for that combination is 1.6 × RER. Resting energy is converted from the weight in kilograms, multiplied by the factor, then rounded to the nearest 5 kcal. That daily figure is 585 kcal.
Cups are daily calories divided by kcal per cup, rounded to the nearest eighth: 1 5/8 cups a day, or 7/8 cups at each meal (295 kcal). Rounding can make the meals differ slightly from the day. Follow the day line.
Treats show as 60 kcal. Merck's feeding-practices chapter says treats should stay under 10% of daily calories, because most treats are not a complete diet.
Why the bag and this page can disagree
Merck states the limit in plain language: any calculation is a starting point, and one animal may need as much as 30% more or less than another of the same weight. Breed, muscle, weather, illness and how much the dog actually moves all sit outside a single factor.
Replace 350 with the kcal per cup on your bag or can. This page does not assume a typical dry, canned or raw density. A senior dog stays on the adult factor, because Merck's table has no senior row.
Daily calories and cups by weight
| Weight | kcal per day | Cups per day | Treats, up to |
|---|---|---|---|
| 10 lb | 350 kcal | 1 cup | 35 kcal |
| 20 lb | 585 kcal | 1 5/8 cups | 60 kcal |
| 40 lb | 985 kcal | 2 7/8 cups | 100 kcal |
| 60 lb | 1,335 kcal | 3 7/8 cups | 135 kcal |
| 80 lb | 1,655 kcal | 4 3/4 cups | 165 kcal |
Neutered adult, ideal shape, 350 kcal per cup (an example — check the label). Cups are rounded to the nearest 1/8. A dog may need about 30% more or less.
Tips and common mistakes
- Weigh the dog. A rough guess moves the result more than the rounding does.
- Type kcal per cup from the label. Do not add the treat line on top of a bag that already includes treats.
- Switching lb and kg converts the weight. It does not clear the label calories or the meal count.
When to call your vet
- Weight is changing and you cannot see why from the bowl.
- The dog is a puppy under four months, pregnant, nursing, or working hard. Those situations use different factors. This page does not include pregnancy or hard-work factors.
- Appetite drops, drinking changes a lot, or the body shape and the scale disagree.
- You are planning weight loss. This page does not run a weight-loss plan. Agree any cut with the vet before you shrink the bowl.
Frequently asked questions
How many cups a day for a 20 lb dog?
For the numbers this page opens with — a neutered adult in ideal shape, at the example 350 kcal per cup — the result is 1 5/8 cups a day, which is 585 kcal. Your cup count changes as soon as the label calories change. Twenty pounds is only the starting weight.
Do puppies and seniors need different amounts?
Puppies do, on this table. Under 4 months the factor is 3 times resting energy. Over 4 months it is 2 times. Seniors do not have their own factor in the Merck table this page uses, so a senior stays on the adult factor until a vet sets something else.
Why does my dog need more or less than the result?
The same published note that supplies the formula says an individual dog may need up to 30% more or less than the calculated calories. Activity, body composition and health are the usual reasons. The result is a place to start, not a prescription.
What if I feed more than one meal?
Enter how many meals you already feed. The page divides the day by that count and rounds each meal to the nearest eighth of a cup and the nearest 5 kcal. It does not tell you that two meals, or three, is the right pattern.
Can I use this for raw food or a specific brand?
Only if you type that food's own kcal per cup or, after you convert it, kcal per the scoop you use. The page does not list brands, and it does not assume a raw density. A raw percentage-of-weight method is a different calculation and is not on this page.