21 cans compared

Hill's Science Diet vs Royal Canin

The typical Royal Canin can gets 14.6% of its calories from carbohydrate, against 21.1% for Hill's Science Diet. Hill's Science Diet has 2 of 11 recipes under the 10% low-carb line; Royal Canin has 2 of 10. Below, every number is worked out the same way from each can’s label.

Hill's Science Diet

Royal Canin

Hill's Science Diet vs Royal Canin at a glance

Typical values are the middle recipe of each brand. Shares are of calories, so textures compare fairly. Marked cells show the better value where the gap is meaningful.

	Hill's Science Diet	Royal Canin
Cans we compare	11	10
Typical carbs, % of calories	21.1%	14.6%
Carb range	3.9–35%	8.8–24.1%
Recipes under 10% carbs	2 of 11	2 of 10
Typical protein, % of calories	43%	53%
Typical fat, % of calories	37%	29%
Calories per ounce	30	22
Calories per can	72–212	55–78
Recipes with published phosphorus	0 of 11	0 of 10
Typical phosphorus, mg per 100 kcal	—	—
Confirmed for kittens	3 of 11	2 of 10
Chicken-free recipes	0 of 11	0 of 10
Fish-free recipes	2 of 11	2 of 10
Textures	Pâté, Chunks in gravy	Pâté, Chunks in gravy

Lowest-carb can from each brand

The recipe with the smallest share of calories from carbohydrate on each side, leaving out toppers meant for supplemental feeding.

Put these two side by side

Hill's Science Diet5.5 oz

Kitten with Salmon

Pâté · 212 kcal per can

Carbs: 3.9%
Protein: 43%
Phosphorus: not listed

Protein 43%Fat 53%Carbs 4%

Low carb

Royal Canin3 oz

Kitten Loaf in Sauce

Pâté · 78 kcal per can

Carbs: 8.8%
Protein: 53%
Phosphorus: not listed

Protein 53%Fat 38%Carbs 9%

Low carbHigh protein

Same texture, head to head

For each texture both brands make, the lowest-carb recipe from each.

Texture	Hill's Science Diet	Royal Canin
Pâté	Kitten with Salmon3.9% carbs · 43% protein · 212 kcal	Kitten Loaf in Sauce8.8% carbs · 53% protein · 78 kcal
Chunks in gravy	Tender Chicken Dinner16.4% carbs · 44% protein · 170 kcal	Adult Instinctive Thin Slices in Gravy10.6% carbs · 62% protein · 66 kcal

Which to choose, by what your cat needs

For a diabetic or overweight cat

Royal Canin is the lower-carb line overall. Its lowest-carb recipe is Kitten Loaf in Sauce at 8.8% of calories; Hill's Science Diet’s is Kitten with Salmon at 3.9%. Both brands have recipes under the 10% line (2 of 10 against 2 of 11), so the right recipe matters more than the brand.

For kidney concerns

Hill's Science Diet doesn’t publish phosphorus on the pages we checked. Royal Canin doesn’t publish phosphorus on the pages we checked. Without published values neither brand can be checked for phosphorus from the label alone; ask the maker for a typical analysis.

For kittens

Hill's Science Diet has 3 of 11 recipes whose label we could confirm covers growth or all life stages; Royal Canin has 2 of 10. A missing statement doesn’t mean a can is unsuitable, only that we couldn’t verify it.

For allergies and picky eaters

Chicken-free: Hill's Science Diet 0 of 11, Royal Canin 0 of 10. Fish-free: Hill's Science Diet 2 of 11, Royal Canin 2 of 10. Textures: Hill's Science Diet makes pâté, chunks in gravy; Royal Canin makes pâté, chunks in gravy.

Questions about Hill's Science Diet vs Royal Canin

Is Hill's Science Diet or Royal Canin lower in carbs?

Which has more protein, Hill's Science Diet or Royal Canin?

Hill's Science Diet. Its typical can gets 43% of calories from protein, against 53% for Royal Canin. Hill's Science Diet has 0 of 11 recipes over 50% protein calories; Royal Canin has 8 of 10.

Which is more filling per ounce?

Royal Canin. Its cans average 22 calories per ounce against 30 for Hill's Science Diet, so a cat needs fewer ounces of it to get the same calories.

Do Hill's Science Diet and Royal Canin publish phosphorus?

Hill's Science Diet doesn’t publish phosphorus on the pages we checked. Royal Canin doesn’t publish phosphorus on the pages we checked.

Which is better for a diabetic cat, Hill's Science Diet or Royal Canin?

Carbs are what matter most, and Royal Canin has the lower-carb line with 2 of 10 recipes under 10%. The best single choice is a specific recipe, not a brand: Kitten with Salmon (3.9%) from Hill's Science Diet or Kitten Loaf in Sauce (8.8%) from Royal Canin. Change a diabetic cat’s food only with your vet.