For most small UK cafes and restaurants, a free calculator or spreadsheet is genuinely enough to get started — if you run fewer than about 30 menu items, update prices monthly, and have one person who actually enjoys the maths. The moment you're juggling supplier price swings, batch recipes, multiple sites, or you simply keep avoiding the spreadsheet, that's when dedicated food cost software earns its keep.
Here's how to decide honestly, without overspending.
Food cost is the percentage of a dish's selling price that goes on ingredients. The standard formula:
Food cost % = (cost of ingredients ÷ selling price) × 100
Most UK cafes and casual restaurants aim for a food cost between 28% and 35%. A flat white made with 18g of beans at £22/kg costs you roughly 40p in coffee, plus milk, cup, and lid. Sell it at £3.20 and your food cost on that item is healthy. But a £9 burger with premium cheese, brioche, two sauces, and chips can quietly creep to 45% before you've paid a single wage.
The danger isn't one bad dish — it's not knowing which dishes are bad. That's the real question behind "do I need software." It's less about the tool and more about whether you currently have accurate, up-to-date numbers.
A free online food cost calculator or a simple Google Sheet works well when:
For this situation, build a spreadsheet with these columns: ingredient, pack price, pack size, cost per gram/ml/unit, quantity in recipe, and line cost. Sum the lines, divide by your selling price, and you've got your food cost percentage. Add a column for your target price at 30% and you've got a basic menu engineering tool for free.
This is real, useful work — and it costs nothing but time.
The free route breaks down in predictable ways, and it usually happens after you've built it, when maintenance becomes the problem.
1. Price changes don't update themselves. UK food inflation has been brutal and uneven. Butter, eggs, oils, and chicken have all swung sharply. A spreadsheet you costed in January can be silently wrong by March. Every supplier price rise means manually hunting down every recipe that uses that ingredient.
2. Sub-recipes get messy. If you make a tomato sauce in 5-litre batches and use it across six dishes, a basic calculator forces you to either re-enter the sauce cost everywhere or guess. Get the batch yield wrong and the error multiplies across the whole menu.
3. Yields and waste are easy to ignore. A whole salmon side isn't 100% usable. Trim, bones, and skin mean your usable yield might be 65%. Free calculators rarely prompt you to account for this, so your costs read lower than reality — exactly the kind of optimism that erodes margin.
4. Scaling for prep is manual and error-prone. Doubling a recipe for a busy weekend, or scaling a function order, means re-doing arithmetic under pressure. Mistakes here cause both waste and shortfalls.
5. VAT and portion confusion. UK hospitality VAT rules (eat-in vs takeaway, hot vs cold) complicate your actual margins. A naive calculator that ignores VAT on the sell price can flatter your numbers.
6. Nobody maintains it. This is the real killer. Spreadsheets get abandoned. If the file isn't being updated, it's worse than useless — it gives false confidence.
Ask yourself these five questions:
1. Does my menu change more than a few times a year?
2. Do my supplier prices move often or unpredictably?
3. Do I use batch recipes and sub-recipes across multiple dishes?
4. Do I run more than one site, or plan to?
5. Have I been avoiding updating my costings for over a month?
Zero to one "yes": A free calculator or spreadsheet is fine. Don't overspend — put the money into ingredients or staff instead.
Two to three "yes": You're in the grey zone. Software will save you hours and catch errors, but a disciplined spreadsheet owner can still cope.
Four or five "yes": Dedicated food cost software will likely pay for itself quickly through reduced waste, faster repricing, and protected margins.
The value isn't the formula — it's everything around it:
For a busy kitchen, the time saved on repricing alone — when a supplier hikes prices overnight — often justifies the cost.
If you're a tiny cafe with a short, stable menu and the discipline to maintain a spreadsheet, a free calculator is genuinely enough. Don't let anyone shame you into paying for software you won't use.
But if your menu is growing, your supplier prices won't sit still, or you've already noticed your costings going stale, the maths stops being the hard part — keeping it accurate is. That's the line where software shifts from luxury to sensible investment.
If you've reached the point where guessing margins and re-doing prep maths is eating your evenings, PrepSheet turns any recipe into a costed, scalable prep sheet — automatic costs, yields, portion math, and batch scaling. If that sounds like the headache you're ready to put down, you're welcome to [join the waitlist](#) and see it when it's ready.