Food Cost Formula: How to Calculate Your True Cost Per Dish
The food cost formula explained for UK caterers. Learn how to calculate cost per dish, food cost percentage, and apply waste factors — with worked examples.
Published 27 March 2026 · Last reviewed 20 March 2026
The food cost formula
The basic food cost formula is:
Food cost per portion = Total ingredient cost / Number of portions
That tells you what each serving costs in raw ingredients. To make pricing decisions, you need two more numbers:
Food cost percentage = (Ingredient cost per portion / Selling price per portion) x 100
Selling price = Ingredient cost per portion / Target food cost percentage
These three formulas are the foundation of every pricing decision a caterer makes. Get them wrong, and every event you quote is based on guesswork.
Food cost percentage: what to target
Food cost percentage tells you how much of your selling price goes to ingredients. The lower the percentage, the higher your gross margin on food.
| Food cost % | Gross margin | Typical use case |
|---|---|---|
| 25% | 75% | High-end canapes, premium dining |
| 30% | 70% | Standard sit-down dinners, private chef menus |
| 35% | 65% | Buffets, family-style service |
| 40% | 60% | High-ingredient dishes (seafood platters, charcuterie) |
Most UK caterers target 28-35% food cost on their menu prices. That does not mean 65-72% of the price is profit — the rest covers labour, travel, equipment, overheads, and your own wages. After all costs, net margins for micro-caterers typically sit between 15-25%.
If your food cost percentage is consistently above 40%, either your ingredient costs are too high or your prices are too low. Below 25% on a main course may mean your portions are too small for the price point.
CaterCost does this automatically.
Recipe costing, event pricing, and allergen tracking — built for UK micro-caterers.
Worked example: costing a beef bourguignon
| Ingredient | Purchase price | Amount used (serves 6) | Cost |
|---|---|---|---|
| Braising steak | £9.00/kg | 900g | £8.10 |
| Smoked bacon lardons | £3.50/250g | 150g | £2.10 |
| Button mushrooms | £1.80/250g | 200g | £1.44 |
| Carrots | £0.80/kg | 300g | £0.24 |
| Onions | £1.00/kg | 200g | £0.20 |
| Red wine | £7.00/bottle | 350ml | £3.27 |
| Beef stock | £1.50/500ml | 300ml | £0.90 |
| Tomato puree | £0.70/tube | 2 tbsp | £0.10 |
| Butter | £2.50/250g | 30g | £0.30 |
| Olive oil | £4.00/litre | 2 tbsp | £0.12 |
| Flour (coating) | £1.10/1.5kg | 30g | £0.02 |
| Bay leaves, thyme, seasoning | — | — | £0.15 |
| Total (serves 6) | £16.94 |
Cost per portion: £16.94 / 6 = £2.82
With 10% waste factor: £2.82 x 1.10 = £3.11 per portion
At 30% food cost target: £3.11 / 0.30 = £10.37 selling price per portion
At 35% food cost target: £3.11 / 0.35 = £8.89 selling price per portion
The difference between 30% and 35% food cost is £1.48 per portion. Across 40 guests, that is £59.20 in revenue. Getting this number right matters.
The waste factor: why 10% is a useful default
Raw ingredients rarely yield 100% of their purchased weight. Preparation creates peelings, trimmings, and offcuts. Cooking causes evaporation and shrinkage. The waste factor accounts for this.
| Ingredient category | Typical waste % | Example |
|---|---|---|
| Root vegetables | 15-25% | Carrots: 1kg purchased = ~800g peeled and trimmed |
| Leafy vegetables | 20-30% | Lettuce: outer leaves, roots removed |
| Meat (bone-in) | 30-40% | Chicken legs: bone and skin weight |
| Meat (boneless) | 5-10% | Chicken breast: trimming only |
| Fish (whole) | 40-50% | Whole sea bass: head, bones, skin |
| Fish (fillets) | 5-10% | Salmon fillets: minimal waste |
| Herbs | 30-50% | Thyme: stems discarded |
| Dry goods | 0-2% | Flour, rice, pasta: negligible waste |
For a mixed menu, a 10% overall waste factor is a reasonable starting point. If your menu is heavy on bone-in meats or whole fish, increase it to 15-20%.
How to track food costs over time
Calculating food cost once per recipe is a start. Tracking it over time is what protects your margins:
Update ingredient prices quarterly. Supplier prices change. A recipe costed in January may be 10-15% more expensive by spring. Set a reminder to spot-check your top 10 ingredients every three months.
Track actual vs planned costs per event. After each event, compare what you actually spent on ingredients to what your costing predicted. If there is a consistent gap, your waste factor is wrong, your portion sizes are off, or you are substituting ingredients without updating costs.
Monitor your overall food cost percentage monthly. Total food spend divided by total food revenue. If this trends upward over several months, investigate before it erodes your margins.
Calculator shortcut
For a quick calculation without the manual maths, use the catering cost per head calculator. Enter your dishes and ingredients, set the guest count and target margin, and see per-head costs and suggested selling prices instantly. The recipe scaling calculator handles the ingredient-level scaling.
Sources
This guide covers food costing for UK-based caterers. It does not constitute financial advice. Ingredient prices used in examples are illustrative — always check current prices with your suppliers.