How do I work out what a meal actually costs per portion?

Most people have a strong intuition about which meals are cheap and it is frequently wrong. Chicken breast feels normal and pulses feel like a sacrifice, but the arithmetic often says something different, and the cost of an hour in the oven is invisible until you count it. Doing this once for the meals you actually cook is worth more than any amount of general budgeting advice.

What you'll need

• Your recipes, or the meals you cook most
• Receipts or a supermarket app for pack prices
• A calculator or a spreadsheet
• Your current electricity and gas unit rates (optional)

Step by step

1. Pick the six meals you actually cook.Not the ones you would like to cook. Six covers most weeks in most households, and pricing six meals takes about twenty minutes and tells you almost everything.
2. Convert every pack price to a unit price.Price divided by pack weight gives pence per 100g. Supermarket shelf labels usually show this already and it is the single most useful number in a shop — it is how you find that the larger pack is sometimes dearer per kilo, which happens more often than people expect.
3. Multiply by what the recipe uses, not what the pack contains.A 400g tin of tomatoes used whole is the tin price; 30g of tomato purée from a 200g tube is 15% of the tube. This is the step that reveals which ingredients are genuinely expensive per meal rather than expensive per pack.
4. Include the cheap things.Oil, salt, stock cubes, spices, a splash of vinegar. Individually trivial, collectively often 20 to 40p a meal, and leaving them out makes every meal look cheaper than it is.
5. Add the cooking energy.A rough guide: an electric oven draws about 2 to 2.5kW and cycles, so an hour of roasting is very roughly 1 to 1.5kWh; a hob ring is around 1 to 2kW; a slow cooker is about 0.2kW; an air fryer or microwave uses a fraction of an oven's energy for small quantities. Multiply the kWh by your unit rate. On a long roast this is a real line item.
6. Divide by honest portions.How many people it actually feeds in your house, not what the recipe claims. A recipe that says four and feeds three in your household costs a third more per portion than the book says.
7. Compare the results and look for the surprises.Nearly always: pulse- and grain-based meals come in far lower than expected, meat-centred meals higher, and anything with a lot of cheese or cream higher still. Long oven meals carry a meaningful energy cost that batch cooking spreads across several portions.
8. Recost twice a year, not weekly.Prices move. A recost every six months keeps the picture honest without turning it into a chore. Keep the workings in a spreadsheet so it is a five-minute job the second time.

Tips

• Cost per portion of protein is the most useful single comparison. Tinned pulses, eggs, frozen fish and chicken thighs usually land far apart from each other.
• Batch cooking spreads the oven energy across many portions, which is a real and usually uncounted saving.
• A slow cooker or air fryer used instead of a full oven for a small meal is often the largest single energy saving available in a kitchen.
• Do not forget waste in the calculation — an ingredient half of which gets thrown away costs twice what the label says.

Common mistakes

• Ignoring the store cupboard ingredients — Oil, spices, stock and condiments are bought infrequently and feel free, so they are omitted. Across a week of meals they are a real cost, and omitting them makes every home-cooked meal look artificially cheap next to a ready meal.
• Using the recipe's stated portions — Recipe portions are notional and often optimistic. Costing against how many people your version actually feeds is the only way to compare a home-cooked meal honestly against a shop-bought alternative.

Questions people ask