Comparing cat food by shelf price alone can be misleading. This guide shows how to calculate the real cost per day using pack price, portion size and calorie information, so you can find affordable complete cat food without cutting corners on nutrition.
Overview
The cheapest-looking bag or pouch is not always the best value. A large pack may require a larger daily portion, while a smaller, more energy-dense food may feed a cat for longer. Wet and dry food also contain very different amounts of water, so comparing price per kilogram does not give a fair picture.
A useful comparison has three stages:
- Check that the food is suitable for your cat and labelled as complete for the relevant life stage.
- Calculate the cost of the portion your cat actually eats each day.
- Compare similar feeding plans, including mixed feeding and regular treats.
This approach works whether you are comparing supermarket cat food, premium cat food brands, a retailer offer or a cat food subscription. It also helps you revisit a choice when a price, pack size or feeding recommendation changes.
Cost should not be the only consideration. A food that causes digestive upset, is refused by your cat or is unsuitable for a medical condition may create extra expense and disruption. For broader nutrition guidance, see our practical guide to choosing the best cat food in the UK.
How to estimate cat food cost per day
The simplest formula is:
Cost per day = pack price × daily portion in grams ÷ pack weight in grams
For example, if a hypothetical 2 kg bag costs £14 and the feeding guide suggests 55 g per day:
£14 × 55 ÷ 2,000 = £0.385, or approximately 39p per day.
To estimate a monthly cost, multiply the daily figure by the number of days in your chosen period. Using 30 days, 39p per day would be approximately £11.70. Treat this as a planning estimate rather than a guarantee: your cat’s portion may need adjusting, and retailer prices can change.
Use calories when foods have different portions
Price per gram is useful when comparing similar products, but it becomes less helpful when comparing wet food with dry food. A more consistent method is to compare the cost of supplying a similar amount of energy.
Use the calorie information printed on the packaging. The calculation is:
Cost per 100 kcal = pack price × calories required ÷ total calories in the pack
To find the total calories in a pack, multiply the food’s calories per gram by the pack weight in grams. If the packaging gives calories per 100 g, divide that figure by 100 to obtain calories per gram.
Do not use an assumed calorie target as a diagnosis or a replacement for feeding guidance. Start with the manufacturer’s recommendation, then consider your cat’s body condition, activity, age and health with advice from your vet where appropriate.
Inputs and assumptions
A reliable comparison depends on recording the same information for every product. Keep a note of the following:
- Price: record the actual price you pay, including any multibuy condition, delivery charge or subscription discount that you can genuinely use.
- Pack size: check whether the price is for one pouch, a multipack, a tray, a tin or a full bag.
- Daily portion: use the relevant feeding recommendation for your cat’s weight and life stage, not the largest or smallest figure simply because it produces a lower result.
- Calorie density: note calories per gram or per 100 g if you are comparing wet, dry or mixed feeding.
- Food status: confirm whether the label says complete or complementary. Complementary food should not be treated as the sole diet unless your vet has given specific instructions.
- Extras: include treats, toppers and occasional complementary pouches if they are a regular part of the routine.
For a healthy adult cat, the packet guide is a starting point rather than an exact prescription. Monitor weight and body condition over time. Indoor cats, less active cats and cats prone to weight gain may need a different portion from an active outdoor cat. Kittens, elderly cats and cats with medical needs require particular care when changing food or calculating portions. Our UK cat feeding guide provides further context.
Nutrition also matters when shopping for cheap cat food in the UK. A lower price is only a meaningful saving if the food is appropriate, accepted by your cat and nutritionally suitable. For help checking labels, read complete versus complementary cat food.
Worked examples
The figures below are illustrative examples, not current UK prices or product rankings. Replace them with the prices and feeding information on the products you are considering.
Example 1: Two dry foods
| Product | Pack and price | Daily portion | Estimated daily cost |
|---|---|---|---|
| Dry food A | 2 kg at £14 | 55 g | 39p |
| Dry food B | 1.5 kg at £12 | 45 g | 36p |
Food B has the higher price per kilogram, but its suggested portion is smaller in this example. Its estimated daily cost is lower. Before choosing it, check that both foods are complete, suitable for your cat’s life stage and comparable in calorie density. A feeding guide alone should not be used to judge quality.
Example 2: Wet food
Suppose a hypothetical tray contains 24 pouches, costs £18 and the feeding guide suggests three pouches per day. The daily cost is:
£18 × 3 ÷ 24 = £2.25 per day.
If your cat eats two pouches plus a measured dry-food portion, calculate each part separately and add the results. This avoids comparing a wet-only plan with a dry-only plan as though the same number of grams supplies the same energy.
Example 3: A mixed-feeding plan
Imagine a dry food costing 30p per daily portion and a wet food costing £1.20 for the daily wet portion. The food cost is £1.50 per day, or approximately £45 over 30 days. If regular treats add 10p per day, the practical food budget becomes £1.60 per day, or approximately £48 over 30 days.
This is why a comparison table should include the whole routine rather than only the main bag or box:
| Item | Daily cost | 30-day estimate |
|---|---|---|
| Dry portion | £0.30 | £9.00 |
| Wet portion | £1.20 | £36.00 |
| Regular treats | £0.10 | £3.00 |
| Total | £1.60 | £48.00 |
When comparing wet versus dry food, consider palatability, hydration preferences, storage and portion control as well as price. If your cat needs urinary care, an allergy diet, a sensitive-stomach formula or another veterinary diet, ask your vet before switching for the sake of cost. Relevant guidance is available in our articles on urinary care cat food and sensitive stomachs and allergies.
When to recalculate
Recalculate your cat food cost per day whenever one of the key inputs changes. A practical review schedule is:
- When the price changes: update the calculation after a promotion ends, a subscription renews or a retailer changes its pack price.
- When the pack size changes: a new bag or multipack may have a different unit cost even if the shelf price looks similar.
- When your cat’s portion changes: recalculate after a weight-management plan, a change in activity or a new feeding recommendation.
- When switching between wet and dry: use the new product’s portion and calorie information rather than carrying over the old number of grams.
- When treats become routine: include them in the monthly budget and account for them when considering the total daily intake.
- When health needs change: follow veterinary advice first, particularly for prescription, urinary, allergy or digestive diets.
For a quick comparison, copy the following checklist into your notes: product price, pack weight or number of pouches, daily portion, calories if available, complete or complementary status, and any regular extras. Divide the price by the number of portions in the pack, then compare the resulting daily cost across suitable foods.
Finally, review the result against your cat’s real response. Stable weight, good appetite, normal stools and a food your cat will reliably eat are practical measures of value. If you change products, do so gradually where possible; our cat food transition schedule explains how to reduce avoidable disruption.
