How much homemade food to feed a dog: how to work out the portion

Key points

• Resting energy needs are calculated with the formula 70 × weight^0.75 (weight in kg).
• That result is multiplied by a factor based on age, spay/neuter status and activity.
• To convert kcal to grams, divide by the recipe's kcal per 100 g and multiply by 100.
• Any formula is a starting point: weight and body condition tell you whether to adjust.
• Treats shouldn't go above 10% of the day's calories.

How much homemade food to feed a dog is one of the most common questions, and the short answer is that you work it out by calories, not by volume or a fixed percentage of body weight. A calm, neutered 15 kg (33 lb) dog and another of the same weight that runs every day can need hundreds of calories' difference.

Here's the formula vets use, the factors that adjust it for age and activity, how to turn calories into grams of your recipe, a step-by-step example, and how to use body condition to fine-tune it. If you'd rather skip the math, the calculator does it for you.

Step 1: resting energy requirement (RER)

RER (resting energy requirement) is the number of calories a dog burns lying down, just to stay alive. It's calculated with this formula:

RER = 70 × (weight in kg)^0.75

You can raise a number to the power of 0.75 on any phone calculator with the x^y key, or by cubing the weight and then taking the square root of the result twice. If your dog's weight is in pounds, divide by 2.2 first. To save you the math, here are the most common values:

Weight	RER (kcal/day)	Spayed/neutered adult (×1.6)	Intact adult (×1.8)
5 kg (11 lb)	234	374	421
10 kg (22 lb)	394	630	709
15 kg (33 lb)	534	854	960
20 kg (44 lb)	662	1,059	1,192
30 kg (66 lb)	897	1,436	1,615
40 kg (88 lb)	1,113	1,781	2,004

Step 2: the factor for life stage and activity

RER is multiplied by a factor that accounts for everything else: growing, moving, being spayed or neutered, or needing to lose weight.

Situation	Factor
Puppy under 4 months	× 3
Puppy 4 to 12 months	× 2
Spayed/neutered adult	× 1.6
Intact adult	× 1.8
Inactive adult or prone to weight gain	× 1.2-1.4
Weight loss	× 1.0, calculated using the target weight
Senior	× 1.4
Very active or working dog	× 2 to 5

For puppies, the calculation uses their current weight and is repeated every two weeks, because it changes very quickly. In large breeds, growth lasts until 12-18 months and should be slow: we explain why in puppy recipes. For pregnant or nursing dogs, needs shoot up and it's best to work them out with your vet.

Step 3: converting calories to grams

Once you know the kcal per day, you need to know how many calories are in the food you feed. Each of our recipes shows this in kcal per 100 g of cooked food. The math is:

Grams per day = kcal per day ÷ recipe's kcal per 100 g × 100

Homemade recipes have much more water than kibble, which is why portions look huge at first. That's normal: kibble has about 350-400 kcal per 100 g and homemade food between 100 and 170.

An example with a 15 kg (33 lb) dog

Lola is a 15 kg (33 lb) mixed-breed dog, spayed, with two half-hour walks a day and an ideal body condition.

1. RER: 70 × 15^0.75 = 70 × 7.62 = 534 kcal.
2. Factor: spayed adult, × 1.6 = 854 kcal a day.
3. Recipe: her chicken, rice and vegetables; let's say it comes to about 140 kcal per 100 g.
4. Grams: 854 ÷ 140 × 100 = about 610 g (21.5 oz) a day, or two meals of about 305 g (10.75 oz).

If one day you feed a lighter recipe at 110 kcal per 100 g, the portion goes up to about 775 g (27 oz). That's why it pays to check each recipe's figure. And if Lola needed to slim down to 13 kg (28.5 lb), we'd calculate with that target weight and a factor of 1.0: 70 × 13^0.75 = 479 kcal a day. For that, there's the turkey and sweet potato weight-loss recipe.

Step 4: adjusting with body condition

Formulas can be off by as much as 20-30% for some dogs: metabolism is individual. The scale and your hands are your quality control. Vets use a 1-to-9 body condition score:

Score	What it looks like	What to do
1-3: thin	Ribs, spine and hip bones visible; no fat to the touch	Increase the portion by 10% and recheck in two weeks
4-5: ideal	Ribs easy to feel under a thin layer of fat; waist visible from above; tummy tucked up from the side	Keep as is
6-7: overweight	Ribs hard to feel; waist barely visible	Cut by 10% and recheck
8-9: obese	Ribs impossible to feel; no waist; fat over the back and base of the tail	Weight-loss plan with your vet

Each point above 5 equals roughly 10% excess weight. Weigh your dog every two weeks at first and, once stable, once a month. Make adjustments 10% at a time, never all at once.

Treats, scraps and other hidden calories

Treats count. As a rule, they shouldn't go above 10% of the day's calories: about 85 kcal for Lola. If you train a lot with treats, subtract them from the portion or use small pieces of their own food. Our homemade dog treats list the kcal per piece so you can keep track.

If you don't want to do any math, the dog food portion calculator does all these steps using your dog's weight, age and activity, and the weekly meal planner turns the result into portions and a shopping list.

Frequently asked questions

How many grams of homemade food should a dog eat per day?

It depends on the recipe's calories and what your dog needs, but as a rough guide an adult dog eats 3-5% of its body weight in cooked homemade food: about 450-750 g (1-1.65 lb) a day for a 15 kg (33 lb) dog. To fine-tune it, calculate their kcal with the formula 70 × weight^0.75 times the activity factor and divide by the recipe's kcal.

How many times a day should I feed my dog?

An adult dog does well on two meals a day, morning and late afternoon or evening. Puppies under three months need four meals, from three to six months three, and after that they can move to two. Some older dogs or dogs with delicate digestion do better on three small meals.

How do I know if my dog is eating too much?

Run your hands along their sides: if the ribs are hard to feel under the fat and there's no waist from above, they're eating more than they burn. Weigh them every two weeks: if an adult dog is gaining weight, cut the portion by 10%. Very large or soft stools can also be a sign of overfeeding.

Do neutered dogs need to eat less?

Yes. After spaying or neutering, energy needs drop by around 20-30% and appetite often goes up, so weight gain is easy. That's why the factor for a spayed or neutered adult is 1.6 versus 1.8 for an intact one. Adjust the portion from the time of surgery and keep an eye on their weight over the following months.