Dog Food Calculator

Quick answer A 20 kg (44 lb) neutered adult dog needs about 1,059 kcal a day (RER 662 × 1.6). With a kibble of 3,600 kcal/kg that is about 295 g a day, split into two meals. Check the kcal on your own bag, weigh your dog regularly and adjust in small steps.

How to use the dog food calculator

Enter your dog's weight in kg or lb.
Choose the life stage and activity that fits best.
Optional: type the kcal per kg or kcal per cup printed on the food bag to also see grams and cups.
Press Calculate to see calories per day, plus grams and cups if you entered the food energy.

Also searched asdog feeding calculatordog feeding chart by weightdog food amount calculatordog food calculator australiadog food calculator by weightdog food calculator kgdog food calculator per daydog food calculator uk

Worked example

Luna, a neutered adult dog weighing 20 kg, eating a kibble that lists 3,600 kcal/kg.

Dog's current weight: 20 kg
Life stage & activity: Neutered/spayed adult
Food energy (kcal/kg on the bag): 3600

1,059 kcal/day

Energy need: 1,059 kcal/day
Food per day: 295 g (10.4 oz)
Per meal (2 meals): 145 g

Example values are illustrative; this result is produced by the same calculator above.

How we calculate it

RER (kcal/day) = 70 × BW(kg)^0.75; MER = RER × factor (neutered adult 1.6, intact 1.8, inactive/obese-prone 1.2–1.4, light work 2.0, moderate 3.0); grams/day = MER ÷ (kcal per kg ÷ 1000); cups = MER ÷ kcal per cup

Sources: NRC · WSAVA Global Nutrition Guidelines · Merck Veterinary Manual

Reference table

Daily energy for neutered adult dogs (1.6 × RER) and grams of a 3,600 kcal/kg kibble
Weight	kcal/day	g/day (3,600 kcal/kg)
2 kg / 4 lb	188	52
5 kg / 11 lb	374	105
10 kg / 22 lb	630	175
15 kg / 33 lb	854	235
20 kg / 44 lb	1,059	295
25 kg / 55 lb	1,252	350
30 kg / 66 lb	1,436	400
40 kg / 88 lb	1,781	495
50 kg / 110 lb	2,106	585

Understanding your result

The calculator first estimates your dog's resting energy requirement (RER), the energy a healthy dog needs just to stay alive at rest: 70 × body weight in kg raised to the power 0.75. It then multiplies RER by a life-stage factor, such as 1.6 for a neutered adult or 1.8 for an intact adult, to estimate daily maintenance energy (MER).

That energy figure is only useful once it is turned into food. The tool divides it by the energy density printed on your bag (kcal per kg or kcal per cup), so the grams or cups you see are specific to the food you actually own. Two bags of kibble can differ by hundreds of kcal per kg, which is why a generic chart can be wrong for your dog.

Treat the result as a starting point for the next two to four weeks, not a fixed prescription. Weigh your dog, check body condition, and adjust the portion up or down in small steps.

Common mistakes

Using the weight your dog should be rather than the weight it is, unless you are following a vet's weight-loss plan (use the weight loss calculator for that).
Copying kcal per kg from a different product or from the wrong column (as-fed versus dry matter).
Forgetting treats, chews and food used for training; they count towards daily calories.
Measuring kibble in a coffee mug. Cup sizes vary, so weigh the food in grams if you can.
Never rechecking: energy needs change with age, activity, neutering and season.

Good to know

Energy needs are not a straight line with weight, which is why the formula uses a power of 0.75. Breeds of the same weight can still differ in what they need.
Puppies, pregnant or nursing dogs and dogs with medical conditions need different plans. Use the puppy food calculator for growing dogs and ask your vet for the others.
If your dog's weight or appetite changes without a clear reason, speak to your vet before changing the diet.

When to talk to your vet

Your dog loses or gains weight unexpectedly
Appetite changes suddenly
Your dog is pregnant, nursing or has a medical condition

Frequently asked questions

How much should I feed my dog?

It depends on weight, life stage and the food's energy. A 20 kg neutered adult needs about 1,059 kcal a day; divide that by your food's kcal per kg to get grams.

How many cups of food should a dog eat?

Divide the daily calories by the kcal per cup on the bag. Use a standard 8 oz measuring cup and level it — scoops vary a lot.

How often should I feed my dog?

Most adult dogs do well on two meals a day. Split the daily amount evenly.

Why is my result different from the bag's feeding chart?

Bag charts are broad ranges for all dogs. This calculator uses your dog's weight and life stage, but every dog is different — adjust by 10% up or down based on body condition.

Should I feed based on current or ideal weight?

For a dog at a healthy weight, use current weight. For an overweight dog, use the Dog Weight Loss Calculator, which works from ideal weight.

Does this calculator work for puppies?

No. Puppies, pregnant or nursing dogs and dogs with medical conditions need different plans. Use the Puppy Food Calculator for growing dogs and ask your vet for the others.

Reviewed by a licensed veterinarian

Last reviewed 18 Oct 2026 · How we review

Sources

Guides about this

How Long Are Dogs Pregnant? Timeline and Due Date GuideDog pregnancy lasts about 63 days from ovulation and 58 to 68 days from mating. Learn how to count, what is normal and when to call the vet.

Embed this calculator

Free for vets, rescues and pet blogs — no ads inside the widget.

Get embed code

Estimates only. Every pet is different — confirm with your veterinarian. If your pet may have eaten something harmful, contact your vet or an animal poison helpline now.