Iams vs Purina ONE Dog Food (2026): 30 Formulas Compared
Buy Purina ONE for most adult dogs: Chicken & Rice is $0.81 per 1,000 calories against $0.94 for Iams MiniChunks, with 29.5% protein (dry matter) against 27.8%. Choose Iams for a large-breed puppy ($0.70 against $0.89), a senior dog ($1.04 against $1.11) or a high-protein diet (35.6% protein at $0.90).
Purina ONE Chicken & Rice
40 lb bag, $59.00. $0.81 per 1,000 calories. AAFCO feeding tests, 29.5% protein (dry matter), 383 calories a cup.
Iams Adult MiniChunks Chicken & Whole Grain
30 lb bag, $46.97. $0.94 per 1,000 calories. 27.8% protein (dry matter), 381 calories a cup. Iams makes 18 dry dog formulas.
Which should I buy for my dog, Iams or Purina ONE?
Find your dog's type below. Each line names the brand that costs less per 1,000 calories at the Amazon bags we priced, and the brand with more protein on a dry-matter basis.
- Adult dog, chicken: Purina ONE Chicken & Rice against Iams Adult MiniChunks Chicken & Whole Grain. Purina ONE costs $0.13 less per 1,000 calories. Purina ONE has 1.7 points more protein.
- Adult dog, lamb and rice: Purina ONE Lamb & Rice against Iams Adult MiniChunks Lamb & Rice. Purina ONE costs $0.02 less per 1,000 calories. Purina ONE has 1.7 points more protein.
- Large-breed adult: Purina ONE +Plus Adult Large Breed Chicken against Iams Large Breed Adult Chicken & Whole Grain. The two cost the same per 1,000 calories. Purina ONE has 4.5 points more protein.
- Large-breed puppy: Purina ONE +Plus Large Breed Puppy Chicken against Iams Puppy Large Breed Chicken. Iams costs $0.19 less per 1,000 calories. Purina ONE has 0.7 points more protein.
- Senior: Purina ONE +Plus Vibrant Maturity Adult 7+ against Iams Healthy Aging Chicken & Whole Grain. Iams costs $0.07 less per 1,000 calories. Purina ONE has 5.1 points more protein.
- Weight control: Purina ONE +Plus Healthy Weight Turkey against Iams Healthy Weight Chicken & Whole Grain. Purina ONE costs $0.07 less per 1,000 calories. Purina ONE has 8.5 points more protein.
- Digestion: Purina ONE +Plus Digestive Health Chicken against Iams Advanced Health Healthy Digestion Chicken. The two cost the same per 1,000 calories. Iams has 0.5 points more protein.
- High protein: Purina ONE True Instinct Turkey & Venison against Iams High Protein Chicken & Beef. Iams costs $0.05 less per 1,000 calories. Iams has 1.5 points more protein.
Pairs where we priced both bags are listed here. The table below has all 30 formulas, including the ones with no price.
How do the 30 Iams and Purina ONE formulas compare, one for one?
Every dry dog formula in our data from each brand: 18 from Iams and 12 from Purina ONE. Protein, fat and carbs are on a dry-matter basis, worked out from the label minimums. On a phone, swipe the table sideways.
| Brand | Formula | Protein, dry matter | Fat, dry matter | Est. carbs, dry matter | Calories a cup | Bag priced read November 11, 2026 | Per 1,000 calories | First ingredient | AAFCO basis |
|---|---|---|---|---|---|---|---|---|---|
| Adult dog, chicken | |||||||||
| Iams | Adult MiniChunks Chicken & Whole Grain | 27.8% | 15.6% | 43.3% | 381 | 30 lb: $46.97 | $0.94 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | Chicken & Rice | 29.5% | 18.2% | 37.5% | 383 | 40 lb: $59.00 | $0.81 | chicken | Feeding tests |
| Adult dog, lamb and rice | |||||||||
| Iams | Adult MiniChunks Lamb & Rice | 27.8% | 15.6% | 42.2% | 382 | 38.5 lb: $57.99 | $0.91 | lamb | Complete and balanced (basis not stated) |
| Purina ONE | Lamb & Rice | 29.5% | 18.2% | 37.5% | 369 | 31.1 lb: $48.98 | $0.89 | lamb | Feeding tests |
| Large-breed adult | |||||||||
| Iams | Large Breed Adult Chicken & Whole Grain | 25.0% | 13.3% | 47.2% | 353 | 30 lb: $46.97 | $0.97 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Adult Large Breed Chicken | 29.5% | 13.6% | 42.6% | 320 | 40 lb: $61.00 | $0.97 | chicken | Formulated |
| Small-breed adult | |||||||||
| Iams | Small Breed Adult Chicken & Whole Grain | 30.0% | 18.9% | 37.8% | 396 | 15 lb: $29.97 | $1.16 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | Small Bites Beef & Rice | 29.5% | 18.2% | 26.1% | 393 | not priced | not priced | beef | Feeding tests |
| Puppy | |||||||||
| Iams | Puppy Chicken | 32.2% | 19.4% | 35.0% | 397 | not priced | not priced | chicken | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Healthy Puppy Chicken | 31.8% | 19.3% | 36.4% | 397 | 31.1 lb: $49.98 | $0.86 | chicken | Formulated |
| Large-breed puppy | |||||||||
| Iams | Puppy Large Breed Chicken | 31.1% | 15.6% | 40.0% | 378 | 30.6 lb: $35.24 | $0.70 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Large Breed Puppy Chicken | 31.8% | 14.8% | 37.5% | 361 | 40 lb: $61.00 | $0.89 | chicken | Formulated |
| Senior | |||||||||
| Iams | Healthy Aging Chicken & Whole Grain | 26.7% | 11.7% | 47.2% | 349 | 29.1 lb: $46.97 | $1.04 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Vibrant Maturity Adult 7+ | 31.8% | 14.8% | 39.2% | 363 | 16.5 lb: $31.58 | $1.11 | chicken | Formulated |
| Weight control | |||||||||
| Iams | Healthy Weight Chicken & Whole Grain | 22.2% | 10.0% | 53.3% | 304 | 29.1 lb: $46.97 | $1.05 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Healthy Weight Turkey | 30.7% | 9.1% | 37.5% | 326 | 40 lb: $61.00 | $0.98 | turkey | Feeding tests |
| Digestion | |||||||||
| Iams | Advanced Health Healthy Digestion Chicken | 28.9% | 15.6% | 42.2% | 380 | 36 lb: $61.98 | $1.04 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Digestive Health Chicken | 28.4% | 18.2% | 39.2% | 384 | 16.5 lb: $31.58 | $1.04 | chicken | Feeding tests |
| High protein | |||||||||
| Iams | High Protein Chicken & Beef | 35.6% | 20.0% | 30.0% | 417 | 30 lb: $46.97 | $0.90 | chicken | Complete and balanced (basis not stated) |
| Purina ONE | True Instinct Turkey & Venison | 34.1% | 19.3% | 29.5% | 365 | 36 lb: $63.00 | $0.95 | turkey | Feeding tests |
| Purina ONE | True Instinct Salmon & Tuna | 34.1% | 19.3% | 29.5% | 338 | 36 lb: $63.49 | $1.04 | salmon | Feeding tests |
| Formulas with no close match from the other brand | |||||||||
| Iams | Puppy Small Breed Chicken | 33.3% | 20.0% | 33.3% | 454 | not priced | not priced | chicken | Complete and balanced (basis not stated) |
| Iams | Healthy Aging Large Breed | 28.9% | 12.2% | 43.9% | 347 | not priced | not priced | chicken | Complete and balanced (basis not stated) |
| Iams | Healthy Weight Large Breed | 25.0% | 10.0% | 50.6% | 327 | not priced | not priced | chicken | Complete and balanced (basis not stated) |
| Iams | Advanced Health Mobility Support Chicken | 23.3% | 15.0% | 48.9% | 375 | not priced | not priced | chicken | Complete and balanced (basis not stated) |
| Iams | Advanced Health Skin & Coat Chicken & Salmon | 27.8% | 15.0% | 44.4% | 373 | 36 lb: $57.97 | $0.97 | chicken | Complete and balanced (basis not stated) |
| Iams | Large Breed Lamb & Rice | 25.0% | 13.9% | 46.7% | 335 | 40 lb: $60.49 | $0.94 | lamb | Complete and balanced (basis not stated) |
| Iams | Small Breed Lamb & Rice | 30.0% | 18.9% | 37.8% | 399 | not priced | not priced | lamb | Complete and balanced (basis not stated) |
| Iams | Adult MiniChunks Beef & Rice | 27.8% | 15.0% | 43.9% | 381 | 30 lb: $46.97 | $0.94 | beef | Complete and balanced (basis not stated) |
| Purina ONE | +Plus Whole Body Support Chicken | 30.7% | 20.5% | 36.4% | 437 | not priced | not priced | chicken | Feeding tests |
Amazon prices as of 2026-11-11. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product.
Cost per 1,000 calories = bag price / (bag pounds x 0.45359 x label calories per kilogram) x 1,000. Iams: iams.com product pages. Purina ONE: Purina's label decks, where the 2026 labels list dietary fiber and a calculated carbohydrate total, so carbs there are Purina's total minus its fiber. "Feeding tests" means the label says AAFCO animal feeding tests back it; "Formulated" means it is formulated to meet AAFCO levels. The Iams pages we read say the food is "complete and balanced for adult dogs" without naming the basis, so that cell says the basis is not stated. No bag is priced for Iams Puppy Small Breed Chicken, Iams Puppy Chicken, Iams Healthy Aging Large Breed, Iams Healthy Weight Large Breed, Iams Advanced Health Mobility Support Chicken, Iams Small Breed Lamb & Rice, Purina ONE Small Bites Beef & Rice and Purina ONE +Plus Whole Body Support Chicken, because we could not match a listing to the formula with certainty.
What do Iams and Purina ONE cost per day?
A 50 lb adult dog eats about 1,160 calories a day by our calculator. At the bags we priced, 30 days of Purina ONE Chicken & Rice comes to about $28.16 and 30 days of Iams MiniChunks to about $32.68. Pair by pair, Purina ONE costs less in 3 of 8 priced pairs, Iams in 3, 2 tied. A small bag of either brand runs higher per calorie.
Have Iams or Purina ONE dog foods been recalled?
Both brands have old recalls and none newer than 2013 in the FDA records we keep (checked November 11, 2026). Full lists: Iams recalls and Purina ONE recalls.
Iams: 8 recalls, 3 naming dry dog food
- August 14, 2013: Iams dry dog foods and dry cat foods, specific lots (also Eukanuba). Reason: potential Salmonella contamination. (FDA notice)
- December 6, 2011: Iams ProActive Health Smart Puppy dry dog food, one production lot. Reason: aflatoxin above the acceptable limit. (FDA notice)
- August 31, 2010: Iams Indoor Weight Control with Hairball Care dry cat food, 6.8 lb bag, one code date. Reason: potential Salmonella contamination. (FDA notice)
- August 29, 2010: Iams Proactive Health Indoor Weight & Hairball Care dry cat food, small number of bags in Loveland, Colorado. Reason: potential Salmonella contamination. (FDA notice)
- July 30, 2010: Expanded recall: Iams Veterinary dry formulas (all dry sizes) and some specialized Eukanuba dry dog and cat foods. Reason: potential Salmonella contamination. (FDA notice)
- July 25, 2010: Iams Veterinary Formulas Feline Renal dry cat food, 5.5 lb, two lots. Reason: potential Salmonella contamination. (FDA notice)
- June 9, 2010: Iams canned cat food, specific lots. Reason: low levels of thiamine (vitamin B1). (FDA notice)
- March 16, 2007: Iams wet dog food pouches and cans (Select Bites, Chunky, Small Bites) and wet cat food cans (Slices and Flakes), made by Menu Foods, part of the 2007 melamine recall. Reason: possible melamine contamination; kidney failure reports. (FDA notice)
Purina ONE: 2 recalls, 1 naming dry dog food
- August 30, 2013: Purina ONE beyOnd White Meat Chicken & Whole Barley Recipe adult dry dog food, 3.5 lb bags, one production run. Reason: potential Salmonella contamination. (FDA notice)
- July 29, 2011: Purina ONE Vibrant Maturity 7+ dry cat food, 3.5 and 7 lb bags, one production run. Reason: potential Salmonella contamination. (FDA notice)
Do Iams and Purina ONE meet the WSAVA guidelines?
WSAVA suggests five questions to put to a pet food maker. On what we could verify, Iams answers yes to 2 and Purina ONE to 4. Iams scorecard, Purina ONE scorecard and all brands.
Iams
We could not confirm this from a public source. source
no QC process described.
666 PubMed papers (animal/pet filtered) list Waltham Petcare Science Institute (Mars Petcare) in an author address; we checked 200 and 200 really name the company. A floor, not a total. source
“The site produces several iconic pet food brands including PEDIGREE, DENTASTIX, IAMS and CESAR, among others.” source
No feeding-trial AAFCO statement found on the 70 labels we’ve verified for this brand, and no company-wide claim was found either. Most pet foods are only "formulated to meet" AAFCO profiles (a paper calculation) rather than fed to real animals in trials — this is common, not necessarily a red flag.
Purina ONE
“Purina Senior Research Scientist Arleigh Reynolds, a veterinarian who is board-certified in veterinary nutrition and who trained the sprint dog team...” source
The company website blocked our automated check, so we could not read its quality-control page. This is not a "no".
144 PubMed papers (animal/pet filtered) list Nestlé Purina in an author address; we checked 144 and 143 really name the company. A floor, not a total. source
“Nestlé Purina PetCare Company today commemorated the opening of its 21st factory in the United States in Hartwell, Georgia... Purina also operates a manufacturing facility in Fairburn, Georgia, which employs 350 people.” source
14 of 19 labels we checked carry an AAFCO feeding-trial substantiation statement. source
Questions owners ask about Iams and Purina ONE
Which is cheaper, Iams or Purina ONE?
Purina ONE costs less in 3 of 8 priced pairs, Iams in 3, 2 tied. The widest gap is in the large-breed puppy pair, where Iams is $0.19 lower per 1,000 calories. The bags we priced run 16.5 to 40 lb for Purina ONE and 15 to 40 lb for Iams, so compare pairs rather than single bags.
Iams or Purina ONE for puppies?
Both make a regular puppy food and a large-breed puppy food. Iams Puppy has 32.2% protein on a dry-matter basis and 397 calories a cup; Purina ONE +Plus Healthy Puppy has 31.8% and 397. For large breeds, Iams Puppy Large Breed has 31.1% and costs $0.70 per 1,000 calories; Purina ONE +Plus Large Breed Puppy has 31.8% and costs $0.89. Purina ONE's two puppy labels are "formulated to meet" AAFCO levels rather than feeding-tested. Ask your vet which puppy food fits your breed.
Does Iams or Purina ONE meet WSAVA guidelines?
WSAVA publishes questions for pet food makers, not a list of approved brands. On what public sources let us check, Iams answers yes to 2 of the five and Purina ONE to 4; the quotes and links are in the WSAVA section above.
Which has more protein, Iams or Purina ONE?
On a dry-matter basis the Purina ONE formulas run 28.4% to 34.1% and the Iams formulas 22.2% to 35.6%. Dry-matter protein takes the water out so two foods can be compared. The highest in each line are Iams High Protein Chicken & Beef and Purina ONE True Instinct Turkey & Venison.
How do I switch my dog from Iams to Purina ONE?
Iams tells owners to mix a new food into the old one gradually, over 4 days (iams.com). Start with a quarter of the new food, move to half, then three quarters, then all. A dog with a touchy stomach may need longer, and your vet can tell you how long.
More: is Purina ONE good for dogs · Pro Plan vs Royal Canin vs Hill's vs Blue Buffalo · dog food cost calculator.
Sources
- Iams labels: the Iams product pages at iams.com, as stored in our dog food data (MiniChunks Chicken is one example).
- Purina ONE labels: Purina's own label decks at live.purina.com, read November 5, 2026 (Chicken & Rice is one example).
- Prices: Amazon, through Amazon's product API, sold by Amazon.com, on the dates shown. Each bag's title names the same formula and size.
- Recalls: FDA notices linked above, from the FDA recall records this site keeps.
- WSAVA: Selecting a pet food for your pet, with each brand's answers sourced in the cards above.