Feeding by breed and weight / Terrier group
How much to feed a Jack Russell Terrier
A neutered adult Jack Russell Terrier at 18 lb needs about 541 kcal a day, which is 1½ cups of a 369 kcal/cup food; at the 14 lb end of the breed's range it is 448 kcal, or 1¼ cups. That is the maintenance figure before treats, from the resting energy requirement formula and the Merck Veterinary Manual's factor of 1.6 for a neutered adult.
Jack Russell Terrier feeding table by weight and life stage
Each row is a Jack Russell Terrier at that weight. Columns are the Merck factors: a neutered adult (×1.6), an intact adult (×1.8) and a dog that is inactive or gains weight easily (×1.4). Cups assume 369 kcal per cup, the label figure for Purina Pro Plan Complete Essentials Shredded Blend Chicken & Rice (adult dry); change it to your bag's number on the sizer.
| Weight | RER | Neutered adult | Cups | Intact adult | Cups | Inactive / weight-prone | Cups |
|---|---|---|---|---|---|---|---|
| 14 lb (6.4 kg) | 280 | 448 kcal | 1¼ | 504 kcal | 1¼ | 392 kcal | 1 |
| 15 lb (6.8 kg) | 295 | 472 kcal | 1¼ | 531 kcal | 1½ | 413 kcal | 1 |
| 16 lb (7.3 kg) | 310 | 495 kcal | 1¼ | 557 kcal | 1½ | 433 kcal | 1¼ |
| 17 lb (7.7 kg) | 324 | 518 kcal | 1½ | 583 kcal | 1½ | 453 kcal | 1¼ |
| 18 lb (8.2 kg) | 338 | 541 kcal | 1½ | 609 kcal | 1¾ | 473 kcal | 1¼ |
RER = 70 × kg0.75; factors from the Merck Veterinary Manual. Calorie density from the Purina product page (3790 kcal/kg, 369 kcal per 8 oz cup, about 96 g). Checked 2026-10-20.
Why the number is lower than the bag says
Bag feeding guides are written for an active, intact adult and often run above the neutered-maintenance figure; for a 18 lb Jack Russell Terrier the gap between the intact and neutered columns is 68 kcal a day, roughly 0.2 cups. A dog that is already carrying extra weight should start from the inactive column (473 kcal at 18 lb) and be weighed every two weeks. Treats and chews count: a single dental chew can be 70–100 kcal, a sizeable share of a small dog's day.
Formulas get a healthy adult into the right range; body condition keeps it there. Ribs should be easy to feel under a thin layer of fat, and the dog should have a visible waist from above. If that is not the case after four weeks, adjust by about 10% and re-check — and ask your vet before changing a dog with a medical condition, a pregnant or nursing female, or a working dog in season.
Grams and meals
At 18 lb and 541 kcal, 1½ cups is about 144 g a day of a 96 g/cup kibble — a kitchen scale is more repeatable than a scoop. Split into two meals for an adult. Puppies eat more per pound and more often: see the Jack Russell Terrier puppy feeding chart.
How the Jack Russell Terrier compares
Calories per pound fall as dogs get bigger, because RER scales with weight to the 0.75 power rather than linearly. A 18 lb Jack Russell Terrier needs 30 kcal per pound; a 18 lb Pug needs 541 kcal (30 per lb), a 18 lb Cavalier King Charles Spaniel needs 541 kcal (30 per lb), a 25 lb Boston Terrier needs 692 kcal (28 per lb). The breed ranks 14 of 49 by weight on this site.
Adult weight from Wikipedia breed infobox/body, checked 2026-10-20. Figures are maintenance starting points for a healthy adult; they are not veterinary advice.