Feeding by breed and weight / by weight

Feeding by weight · 20.4 kg

How much to feed a 45 lb dog

A 45 lb (20.4 kg) dog has a resting energy requirement of 672 kcal. As a neutered adult with normal activity that becomes 1076 kcal a day, or 3 cups of a 369 kcal/cup kibble; an intact adult needs 1210 kcal, and a dog that is inactive or gains weight easily 941 kcal. Puppies that currently weigh 45 lb need far more: 2017 kcal under four months, 1344 kcal after.

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  1. 1Body weight 45 lb (20.4 kg)
  2. 2Neutered adult 1076 kcal a day
  3. 3Cups 3 cups at 369 kcal/cup
RER at 45 lb
672 kcal
Neutered adult
1076 kcal · 3 cups
Intact adult
1210 kcal · 3¼ cups
Inactive / weight-prone
941 kcal · 2½ cups
Neutered1076 kcalIntact1210 kcalAdult941 kcalPuppy under 4 months2017 kcalPuppy 4 months to adult size1344 kcal
Calories a day for a 45 lb dog by life stage and activity: RER × the Merck factor.

45 lb dog feeding table

Life stage / activityFactorkcal/dayCups at 369Cups at 300Cups at 450Grams (96 g/cup)
Neutered adult, normal activity× 1.6107633½2½288 g
Intact adult, normal activity× 1.812103¼42¾312 g
Adult, inactive or prone to weight gain× 1.49412½3¼2240 g
Puppy under 4 months× 320175½6¾4½528 g
Puppy 4 months to adult size× 213443¾4½3360 g

RER = 70 × 20.40.75 = 672 kcal. Factors: Merck Veterinary Manual. The 369 kcal/cup column is Purina Pro Plan Complete Essentials Shredded Blend Chicken & Rice (adult dry) (369 kcal/cup per Purina's label); the 300 and 450 columns bracket the usual range printed on adult dry foods. Checked 2026-10-20.

Reading the table

Pick the row that describes the dog, then the column that matches the kcal per cup on your bag — it is printed near the guaranteed analysis, usually as "kcal/cup" or "kcal ME/cup". The puppy rows apply to a puppy that weighs 45 lb today; a growing puppy should be re-weighed and the amount recalculated every two weeks, which the breed puppy charts do for you. The difference between the neutered and intact rows is 134 kcal, roughly 0.4 cups, which is the most common reason a dog fed "by the bag" gains weight.

These are maintenance starting points for a healthy dog. Weigh the dog monthly and check body condition — ribs easy to feel, visible waist — and adjust by about 10% if it is drifting. Pregnant or nursing dogs, working dogs and dogs with a diagnosed condition need a vet's number, not a table.

Other sizes for a 45 lb dog

By the manufacturer's weight bands a 45 lb dog takes a 36 in crate (Intermediate, 36.6 × 21.9 × 24.5 in interior; measure the dog's length to confirm), and a Medium rectangle bed (36 × 24 in) on Orvis's chart. Harness size depends on chest girth rather than weight — see the harness size chart.

Breeds whose standard weight includes 45 lb