A cat eats little, but the food bill is a steady, lifelong cost, and the difference between the cheapest and the dearest way to feed a cat can be several hundred a year. The difference between wet and dry is not just the price on the shelf: wet food contains mostly water, so you buy and serve three to four times the weight for the same calories. That is why comparing price per kilogram misleads, and why the honest comparison is cost per 1,000 kcal. This guide shows the arithmetic, gives tables for cats of 3 to 6 kg on dry, wet and mixed diets and explains how to spot real savings. Prices are illustrations in one currency.
The formula
monthly cost = grams a day × 30 ÷ 1,000 × price per kg
To get the grams, start from calories. A neutered adult needs 1.2 × 70 × weight ^ 0.75 kcal; a 4 kg cat needs 238. Divide by the food’s kcal per gram to get grams. The Cat Food Calculator gives the grams, and the Cat Food Cost Calculator turns them into money. Our guide to how many grams of dry food a cat needs has a table of grams by weight.
Dry food: monthly cost by weight
For a neutered adult on a 3,800 kcal/kg dry food:
| Cat | Daily kcal | Grams a day | Kg a month | At 4 per kg | At 6 per kg | At 8 per kg |
|---|---|---|---|---|---|---|
| 3 kg | 191 | 50 | 1.5 | 6.05 | 9.07 | 12.09 |
| 4 kg | 238 | 63 | 1.9 | 7.50 | 11.25 | 15.01 |
| 5 kg | 281 | 74 | 2.2 | 8.87 | 13.30 | 17.74 |
| 6 kg | 322 | 85 | 2.5 | 10.17 | 15.25 | 20.34 |
Dry food is usually the cheapest way to feed a cat per 1,000 kcal, though premium products can narrow the gap. Annual cost for the 4 kg cat at 6 per kg is 135.
Wet food: monthly cost by weight
For the same cats on a 1,000 kcal/kg wet food, the grams equal the calories:
| Cat | Daily kcal | Grams a day | Kg a month | At 3 per kg | At 5 per kg | At 7 per kg |
|---|---|---|---|---|---|---|
| 3 kg | 191 | 191 | 5.7 | 17.23 | 28.72 | 40.21 |
| 4 kg | 238 | 238 | 7.1 | 21.38 | 35.64 | 49.89 |
| 5 kg | 281 | 281 | 8.4 | 25.28 | 42.13 | 58.98 |
| 6 kg | 322 | 322 | 9.7 | 28.98 | 48.30 | 67.63 |
A 4 kg cat on wet food only, at 5 per kg, costs 35.64 a month, or 428 a year, compared with 135 on dry at 6 per kg. The weight of food is also much greater: 7.1 kg a month against 1.9. Use cans or pouches priced per unit? Convert to price per kg, or use the Cat Food Cans per Day Calculator and multiply by the can price.
Mixed feeding: working out each part
For a 4 kg cat taking half its calories from each (119 kcal each), dry at 6 per kg and wet at 5 per kg:
| Part | kcal | Grams a day | Cost per month |
|---|---|---|---|
| Dry (3,800 kcal/kg) | 119 | 31 | 5.63 |
| Wet (1,000 kcal/kg) | 119 | 119 | 17.85 |
| Total | 238 | 150 | 23.48 |
Half wet roughly doubles the bill compared with all dry (23.48 against 11.25 in this example). A 25% wet share is cheaper: 59.5 kcal of wet food is 60 g and costs 8.93 a month, and 178.5 kcal of dry food is 47 g and costs 8.46, a total of 17.39. See wet vs dry cat food for the full comparison.
Cost per 1,000 kcal
The fair comparison across foods is price per kg ÷ kcal per kg × 1,000.
| Food | Price per kg | kcal per kg | Cost per 1,000 kcal |
|---|---|---|---|
| Dry standard | 5.00 | 3,800 | 1.32 |
| Dry premium | 9.00 | 4,000 | 2.25 |
| Wet standard | 5.00 | 1,000 | 5.00 |
| Wet premium | 9.00 | 1,100 | 8.18 |
| Wet budget pouch | 3.00 | 800 | 3.75 |
A budget wet food can be cheaper per 1,000 kcal than a premium wet one, and a premium dry food can be cheaper than a budget wet one. The Pet Food Price per 1,000 kcal Calculator does the sum for any two foods. Remember that the food must be complete and balanced for your cat and suit its health; price is only one factor.
Treats and extras
Treats can use up to 10% of daily calories; for a 4 kg cat that is 24 kcal. Cat treats are often rich: 24 kcal may be just four or five pieces. Their cost per 1,000 kcal can be many times that of the main food, so a few a day can add noticeably to the bill. Count them as a separate line.
Kittens, seniors and special diets
Kittens need 2.5 times resting energy, more than twice the neutered adult factor, so a 2 kg kitten needs 295 kcal, comparable to an adult cat of 5 kg. Seniors vary; ask your vet. Prescription diets for health conditions usually cost more than standard foods, and your vet will explain why a particular diet is needed. See senior cat care and the kitten feeding chart.
Reducing waste
Waste raises the real cost. Measure portions, cover opened cans and use them within the label’s time, store dry food sealed and in a cool place and do not buy more than you can use before the best-before date. If your cat refuses a new food, buy a small pack first. A refused 10 kg bag is an expensive mistake.
Putting it in the budget
Add the food total to the Monthly Pet Budget Calculator, and use the Cost of Owning a Cat Calculator for lifetime cost. At 11.25 a month, dry food costs 135 a year and 2,025 over 15 years; at 35.64 a month, wet food costs 428 a year and 6,415 over 15 years. Our guide to the monthly cost of a cat shows how food fits with litter, vet care and insurance.
Common mistakes
- Comparing price per kg across wet and dry.
- Using the bag’s feeding guide instead of calories.
- Forgetting treats.
- Switching foods suddenly to save money.
- Buying too much of a food the cat may refuse.
- Overfeeding, which wastes money and adds weight.
- Choosing price over suitability.
A worked year for one cat
Follow a cat through a year. Pepper is a neutered 4 kg cat eating a mix: 75% of calories from a dry food at 6.00 per kg (3,800 kcal/kg) and 25% from a wet food at 5.00 per kg (1,000 kcal/kg).
| Item | Working | Amount |
|---|---|---|
| Daily calories | 1.2 × 198 | 238 kcal |
| Dry share | 178.5 kcal ÷ 3.8 | 47 g a day |
| Wet share | 59.5 kcal ÷ 1.0 | 60 g a day |
| Dry cost a month | 47 × 30 ÷ 1,000 × 6.00 | 8.46 |
| Wet cost a month | 60 × 30 ÷ 1,000 × 5.00 | 8.93 |
| Treats (about 24 kcal a day) | assumed | 4.00 |
| Total a month | 21.39 | |
| Total a year | × 12 | 257 |
If Pepper gained 0.5 kg in the year and the owner increased the food by 12% to “keep her satisfied”, the bill would rise by about 12% too, for a cat who did not need it. Weighing monthly and holding the amount steady is both the healthiest and the cheapest route. The Cat Calorie Calculator gives the target again whenever weight changes.
Price changes and switching
Cat food prices change, and so do formulas. When your bill rises, compare cost per 1,000 kcal for your food and one or two others, and check the adequacy statement on each. Cats can be reluctant to change, so buy a small pack first and switch gradually over a week or more, as the principles in how to switch dog food describe (cats may need an even slower change). Never leave a cat without food while waiting for it to accept a new one; call your vet if it refuses to eat for a day.
Before you get a cat
If you are planning to get a cat, estimate food from the adult weight, which for most adult cats is 3 to 6 kg. Dry food runs about 6 to 20 a month in the tables above, wet food 17 to 68, and a mix in between. Add litter and the other lines using the Cost of Owning a Cat Calculator, and see how much it costs to own a cat for the whole picture. If you are choosing between a dog and a cat, our dog vs cat cost comparison puts the lines side by side.
Reading the sums for your own cat
Fill in this worksheet to compute your own bill.
| Step | Your number |
|---|---|
| Cat’s weight (kg) | |
| Daily calories (1.2 × 70 × kg ^ 0.75) | |
| Dry share of calories (%) | |
| Dry kcal per kg | |
| Dry grams a day | |
| Dry price per kg | |
| Dry cost a month | |
| Wet share of calories (%) | |
| Wet kcal per kg or per can | |
| Wet grams or cans a day | |
| Wet price per kg or per can | |
| Wet cost a month | |
| Treats and extras a month | |
| Total a month |
Use the Cat Food Cost Calculator if you prefer a form. Update the sheet when prices, weight or the mix change.
Seasonal and life-stage changes
A cat’s food bill is not constant over its life. Kittens eat more per kilogram and cost more per kilogram of body weight in the first year; adults settle; seniors may need a different diet at a different price. Cats that become less active in winter may need slightly less, and a cat on a weight-loss plan eats less for a while. Revisit the worksheet at each change, and keep last year’s totals for comparison. When you plan a household budget, use the highest realistic month, not the lowest, so that you are never caught short.
Quick summary
- Monthly cost = grams a day × 30 ÷ 1,000 × price per kg.
- A 4 kg cat costs about 7.50 to 15 a month on dry food and 21 to 50 on wet (illustrative prices).
- Mixed feeding: price each share separately.
- Compare cost per 1,000 kcal, not price per kg.
- Count treats, avoid waste and keep weight healthy.
- Use the Cat Food Cost Calculator with your own prices.
Frequently asked questions
How do I calculate cat food cost per month?
Daily grams × 30 ÷ 1,000 × price per kilogram, with grams worked out from the cat's calories.
Is wet cat food much dearer than dry?
Usually per 1,000 kcal, yes, but it depends on the products. Compare using calories.
How much does a 4 kg cat's food cost a month?
With 238 kcal a day: about 7.50 to 15 on dry food at 4 to 8 per kg, and about 21 to 50 on wet food at 3 to 7 per kg (illustrative prices).
How can mixed feeding change the cost?
The wet share raises the bill in proportion to its cost per 1,000 kcal. Work out each part separately.
Do treats count?
Yes. Up to 10% of calories, and they have their own cost.
How do I keep the bill down without cutting care?
Weigh portions, avoid waste, compare cost per 1,000 kcal and keep weight healthy.
Should a senior cat's cost be calculated differently?
Use the same method with your vet's calorie target, and allow for any special diet.
Sources
- NRC (2006) Nutrient Requirements of Dogs and Cats, National Academies Press
- Pure arithmetic on your own prices: month = grams a day × 30 ÷ 1,000 × price per kg
Related calculators
- Cat Food Cost CalculatorSee what it costs per day, month and year to feed your cat, from its calorie need and the price of the bag.
- Cat Food CalculatorWork out your cat's daily calories and how to split them between wet and dry food.
- Pet Food Price per 1,000 kcal CalculatorCompare two foods fairly by price per 1,000 calories instead of price per bag.
Keep reading
- Monthly Cost of a Cat: What to BudgetWhat a cat costs each month: food, litter, parasite control, vet care, insurance and replacements, with a budget table and a worked example.
- Wet vs Dry Cat Food: Calories, Water and CostWet and dry cat food compared on water, calories per gram, grams needed, cost per 1,000 kcal and storage, with a worked example and a mixed-feeding plan.
- How Much Does It Cost to Own a Cat?Work out what a cat really costs: one-off items, monthly spending, litter and food, yearly and lifetime totals from your own numbers and ways to plan.
- Pet Sitter vs Boarding: Cost ComparisonHow to compare boarding, drop-in visits and an overnight sitter: rate × nights, a 3 to 14 night table, extras, break-even rates and what price cannot tell you.