Dog food portion calculator
Daily calories, grams and cost from your dog's weight and the food's label, using the formula vets use. No email needed.
The short answer
A neutered adult dog needs about 927–1059 kcal a day at 20 kg, which is 260–295 g of a 360 kcal per 100 g dry food (AAHA 2021 formula, checked 21 October 2026). Enter your dog's ideal weight and the food's label below for grams and cost per day, or use the 2–60 kg chart.
A starting point for your dog
- Calories a day
- 927–1059 kcal
- Food a day
- Add kcal per 100 g
- Cost a day
- Add kcal and price
- Cost per 30 days
- Add kcal and price
A 20 kg dog's resting energy is about 662 kcal a day (70 × weight0.75). For “adult, neutered”, AAHA gives a factor of 1.4–1.6, so 662 × 1.4–1.6 = 927–1059 kcal a day.
This is a starting point, not a prescription. Weigh food rather than using a scoop, check your dog's weight and body condition regularly, and adjust gradually. Treats and chews count towards the total.
Compare UK dog foodsHow much should I feed my dog by weight? A 2–60 kg chart
Daily calories and grams for adult dogs from 2 kg to 60 kg, worked out with the same AAHA formula as the calculator. Grams are for an example complete dry food of 360 kcal per 100 g, close to Wainwright's Adult Chicken & Rice (361.7 kcal per 100 g on Pets at Home, checked 21 October 2026). If your food has more calories per 100 g, feed less; if fewer, feed more.
| Ideal weight | Resting energy | Neutered adult: kcal a day | Neutered adult: grams a day | Active adult: kcal a day | Active adult: grams a day |
|---|---|---|---|---|---|
| 2 kg | 118 kcal | 165–188 kcal | 45–50 g | 188–235 kcal | 50–65 g |
| 4 kg | 198 kcal | 277–317 kcal | 75–90 g | 317–396 kcal | 90–110 g |
| 6 kg | 268 kcal | 376–429 kcal | 105–120 g | 429–537 kcal | 120–150 g |
| 8 kg | 333 kcal | 466–533 kcal | 130–150 g | 533–666 kcal | 150–185 g |
| 10 kg | 394 kcal | 551–630 kcal | 155–175 g | 630–787 kcal | 175–220 g |
| 12 kg | 451 kcal | 632–722 kcal | 175–200 g | 722–903 kcal | 200–250 g |
| 15 kg | 534 kcal | 747–854 kcal | 210–235 g | 854–1067 kcal | 235–295 g |
| 20 kg | 662 kcal | 927–1059 kcal | 260–295 g | 1059–1324 kcal | 295–370 g |
| 25 kg | 783 kcal | 1096–1252 kcal | 305–350 g | 1252–1565 kcal | 350–435 g |
| 30 kg | 897 kcal | 1256–1436 kcal | 350–400 g | 1436–1795 kcal | 400–500 g |
| 35 kg | 1007 kcal | 1410–1612 kcal | 390–450 g | 1612–2015 kcal | 450–560 g |
| 40 kg | 1113 kcal | 1559–1781 kcal | 435–495 g | 1781–2227 kcal | 495–620 g |
| 45 kg | 1216 kcal | 1703–1946 kcal | 475–540 g | 1946–2432 kcal | 540–675 g |
| 50 kg | 1316 kcal | 1843–2106 kcal | 510–585 g | 2106–2632 kcal | 585–730 g |
| 60 kg | 1509 kcal | 2113–2415 kcal | 585–670 g | 2415–3018 kcal | 670–840 g |
Puppies need more: AAHA's factor is 3.0 under four months and 2.0 from four months to adult, so use the calculator, or see our puppy food comparison and large-breed puppy food guide, which give each maker's amounts by age.
How does the chart compare with the feeding guide on the bag?
For a 20 kg neutered adult the chart gives 260–295 g of a 360 kcal food. The makers' own guides for a 20 kg adult, from our dog food comparison (checked 21 October 2026), land in the same area:
- Burns Original Chicken & Brown Rice: 280 g (14 g per kg)
- Hill's Science Plan Sensitive Stomach & Skin Medium: 285 g
- Purina Pro Plan Medium Adult Sensitive Digestion: 270–305 g
- Wainwright's Adult Chicken & Rice: 170–295 g (12–25 kg band)
Foods differ in energy, so the bag's figure for that food beats a general chart. Use the chart to sense-check it, then weigh portions and watch your dog's body condition.
How much kibble a day, and what will it cost?
Weigh kibble rather than using a cup: kibble size and density vary, so a cupful of one food can weigh quite differently from another.
Cost follows grams. Burns Original at 280 g a day works out at £1.01 a day from zooplus's 12 kg price (21 October 2026). For whole-year costs including food, insurance and vet care, see our cost of owning a dog guide or the pet cost calculator.
Buying online? Our zooplus review covers delivery and repeat-order discounts, and our Lily's Kitchen review works out what feeding wet food costs.
How we calculate this
The calculator uses the energy formula in the American Animal Hospital Association's 2021 nutrition guidelines. First it works out your dog's resting energy requirement: 70 × body weight in kg to the power 0.75. It then multiplies that by a life-stage factor to estimate the calories needed each day. Dividing by the food's energy density gives grams; multiplying by the price per kg gives the cost.
| Life stage | Factor |
|---|---|
| Puppy, under 4 months | 3.0 |
| Puppy, 4 months to adult | 2.0 |
| Adult, neutered | 1.4–1.6 |
| Adult, not neutered | 1.6–1.8 |
| Adult, inactive or gains weight easily | 1.0–1.2 |
| Weight loss (agree a target with your vet) | 1.0 |
| Working dog, light work | 1.6–2.0 |
| Working dog, moderate work | 2.0–5.0 |
How much should I feed a dog that needs to lose weight?
AAHA's weight-loss factor is 1.0 × resting energy at the target weight, agreed with your vet. For a dog with a 20 kg target that is 662 kcal a day, compared with 927–1059 kcal for a neutered adult at that weight.
Lower-calorie “light” foods let a dog eat a fuller bowl on fewer calories; our dog food for weight loss comparison lists their calories and cost per day. Older, stiffer dogs often move less: see do joint supplements work for dogs? and our senior dog food comparison.
If your dog is losing or gaining weight without a reason, or you are worried, contact your vet.
Questions
How much should I feed my dog by weight?
As a starting point, a neutered adult dog needs about 551–630 kcal a day at 10 kg, 927–1059 kcal at 20 kg and 1256–1436 kcal at 30 kg (AAHA 2021 formula). In a dry food of 360 kcal per 100 g that is about 155–175 g, 260–295 g and 350–400 g a day. Use your dog's ideal weight, not its current weight.
How much wet food should I feed my dog by weight?
Wet food holds far fewer calories per gram, so the daily amount is much bigger. At 104 kcal per 100 g (Lily's Kitchen Wild Campfire Stew), a 20 kg neutered adult needs about 890–1020 g a day, or two to three 400 g tins. Enter your food's own kcal figure in the calculator.
Why is my result different from the feeding guide on the pack?
Feeding guides on packs are estimates too, so the two may not match exactly. This calculator uses your dog's own weight and the AAHA formula; treat both as starting points and adjust by watching your dog's weight and body condition.
Where do I find the kcal figure for my dog's food?
It is usually printed as "metabolisable energy" on the pack or listed on the brand's website, either in kcal per 100 g or kcal per kg. If it is given per kg, divide by 10. WSAVA notes that calories are only required on pet food labels in the US, so if a UK pack does not show them, ask the maker.
Do treats count towards the daily amount?
Yes. Treats and chews count towards the daily total too. WSAVA's guidance is that complementary foods such as treats should make up 10% or less of the diet.
What weight should I enter if my dog is overweight?
Use the target (ideal) weight rather than the current weight. If your dog is losing or gaining weight it shouldn't, has a medical condition, or you are planning weight loss, agree the target with your vet.
Why might my dog need fewer calories than the result?
The life-stage factors are averages. AAHA notes that sedentary and indoor pets may need fewer calories than the table suggests, and that portions should be adjusted by monitoring body weight and body condition.
To compare what different foods cost in practice, see our dog food cost per day guide, and for choosing a food, our dog food comparison and guide to choosing dog food. Feeding a cat as well? Try the cat food portion calculator.
What changed in this update
- 21 October 2026: Added a 2–60 kg feeding chart (neutered and active adults, kcal and grams for a 360 kcal per 100 g dry food), a comparison with four makers' 20 kg feeding guides, wet-food and weight-loss answers, and links to the cost guides and new food pages. Formula re-checked against AAHA Box 1.