Dog food cost calculator: what does it cost per day?
By Josh · Reviewed and updated: 2026-09-17
The price per kilogram on the shelf is the wrong number to compare. A food that costs less per kilogram can cost more per day, because the same weight of a less calorie-dense food feeds a dog for fewer meals. This calculator works out the number that actually matters — cost per day — and lets you put two foods side by side.
Cost calculator
How the calculation works
Feeding cost is calories multiplied by price, in three steps:
- Work out the daily amount in grams, from your pet's weight, life stage and activity level together with the food's calorie content.
- Work out the price per gram, from the bag price and the bag weight.
- Multiply them.
Step 1 is the one that people skip, and it is the step that changes the answer. Everything else is arithmetic.
Why the price per kilogram is misleading
Here are two 30 lb bags. B is cheaper on the shelf, and cheaper per kilogram. Both are being fed to the same 10 kg neutered adult dog on a typical routine.
| Food A | Food B | |
|---|---|---|
| Price for the 30 lb bag | $60 | $55 |
| Price per kilogram | $4.41 | $4.04 |
| Calorie content | 370 kcal/cup | 320 kcal/cup |
| Calorie density | 336 kcal/100 g | 291 kcal/100 g |
| Amount the dog needs each day | 187 g | 217 g |
| Cost per day | $0.83 | $0.88 |
| Cost per year | $301.35 | $319.40 |
Food B is 8% cheaper per kilogram and about 6% more expensive to actually feed. Over a year that is roughly $18 more, on a bag that looked like the cheaper option.
The mechanism is straightforward once you see it: a food with less energy per gram has to be fed in larger quantities to deliver the same calories. The bag goes down faster, so you buy more bags. Nothing about the cheaper bag is dishonest — the shelf price is just answering a different question from the one you have.
Cost per 1,000 kcal: the only fair comparison
If you want a single number that compares foods of any brand, any bag size and any calorie density, it is cost per 1,000 kcal. It strips out the packaging and the water content and asks one question: what does 1,000 kcal of energy cost in this food? That is what you are buying.
The calculator above gives you that figure next to the cost per day, and it puts both foods' numbers in the comparison table. When two foods sit at a similar cost per 1,000 kcal, you are choosing between them on quality, ingredients or preference rather than on price — which is the point at which price stops being the deciding factor.
What else moves the number
| Factor | Effect on the daily amount, and on what you spend |
|---|---|
| Spaying or neutering | A neutered adult dog needs roughly 11–12% fewer calories than an intact dog of the same size at the same activity level. At the higher activity levels the standard factors are identical, because workload dominates the requirement. Feeding the pre-neutering amount afterwards is one of the most common reasons a dog gains weight — and it costs more than it needs to. |
| Activity level | The gaps are large. The energy factor runs from 1.4 for a low-activity adult to 2.5 for a working one, so a working dog can cost nearly 80% more to feed than the same dog on a low-activity routine. |
| Life stage | A puppy under four months needs around three times the resting energy of an adult, so the first months are the most expensive period of your dog's life to feed — before accounting for the fact that puppy food usually costs more per kilogram as well. |
| Body condition | An overweight dog costs more to feed, because it takes more calories to move a heavier body — and it is being fed towards a weight that your vet will eventually ask you to reduce. Feeding to the correct target weight brings the cost back down. |
| Treats | Treats are usually a small share of the calories and a surprisingly large share of the spending. Dental chews in particular cost far more per calorie than the food does. If you are trying to cut the cost of feeding, look at treats before you look at the food. |
| Wastage | Every gram the bowl leaves behind is a gram you paid for. Measuring the portion is not only about the dog's weight. |
Bag size, bulk buying and freshness
Larger bags are almost always cheaper per kilogram, and if your pet finishes one inside the freshness window printed on the packaging, the larger bag is simply the better buy. If it will not — and for a small dog or a single cat, a large bag often will not — then the per-kilogram saving can be worth less than the food you end up throwing away.
Work out the days per bag first. The bag duration calculator does that, and tells you whether the bag will be open for longer than is sensible.
A note on very cheap foods
Price is not a measure of quality in either direction. There are inexpensive foods that feed well and expensive foods that do not, and nothing on a price label tells you which is which. Two things are worth knowing when you are comparing on cost:
- A cheaper food is not automatically cheaper per day. Run it through the calculator with its real calorie content before you decide — that is the whole point of the comparison above.
- Calorie content is not the only variable. Foods differ in how digestible they are, and a food that passes through less completely can need to be fed in larger amounts than its calorie figure suggests. Your vet is the right person to ask if a diet change and a cost saving seem too good to be true.
Cats
The arithmetic is the same, and the numbers are usually smaller — a 4 kg cat eats a fraction of what a 20 kg dog does. The practical consequence is that the freshness limit bites long before the cost does: buying a large bag to save per kilogram is a poor trade for a single cat, because the food will be open for months. Cost per day matters less for cats than freshness does.
Frequently asked questions
How much does it cost to feed a dog per month?
For a neutered adult dog on a typical activity level eating a food of 370 kcal/cup at $60 per 30 lb bag, it works out at around $0.83 a day, or about $25 a month for a 10 kg dog. A 30 kg dog on the same food costs roughly $1.88 a day, or about $57 a month, because the daily amount scales with body weight. Use the calculator above for your own food's price and calorie figure.
Is a cheaper bag of dog food actually cheaper?
Only per kilogram, which is not the number that matters. A less calorie-dense food must be fed in larger quantities, so the bag empties sooner and you buy more of them. In the worked example on this page, a bag that was 8% cheaper per kilogram cost about 6% more to actually feed, or roughly $18 more over a year.
What is the best way to compare two dog foods on price?
Compare cost per 1,000 kcal. It is the only figure that accounts for calorie density, so it lets you compare different brands, different bag sizes and different calorie contents on the same basis. The calculator above produces it automatically for both foods.
Does neutering affect how much dog food costs?
Yes, though by less than is often claimed. On the standard factors a neutered adult dog needs roughly 11–12% fewer calories than an intact dog of the same size at the same activity level, so the daily amount — and the cost — is lower. Feeding the pre-neutering amount afterwards is a common cause of gradual weight gain.
Calculate your pet's daily food amount →
How long will this bag last? →
How many treats can your dog have? →