Automatic food cost from supplier invoices: how it works
Benn Asaraf ·
Most costing sheets I see in kitchens have one thing in common. The prices are from the day someone built the sheet. Chicken went up twice since then. The sheet still says £3.90 a kilo.
Your food cost is only as fresh as the last price you typed. The invoice in the folder by the pass already has this week's price. This guide shows how to cost a dish straight from that invoice, by hand. Then it shows what automatic food cost from supplier invoices actually means, and where it can go wrong.
Why your spreadsheet stops updating
A spreadsheet does not read invoices. Somebody has to open it, find the row and type the new price. On a Tuesday after a double, nobody does.
So the sheet drifts. Each line is only a few pence out. Across a menu, that is the difference between 72% GP and 66%. You find out at the stocktake, a month late.
The fix is not a better spreadsheet. It is pulling the price from the invoice every time an invoice arrives.
Cost one dish from one invoice, by hand
Take a real dish and a real invoice. Here is mine: chicken thigh, charred leeks, crème fraîche. Menu price £16.
The delivery from the wholesaler had these lines:
| Item | Pack | Price per pack | VAT |
|---|---|---|---|
| Chicken thigh, boneless | 2 x 5kg | £47.00 | 0% |
| Leeks | 5kg box | £9.50 | 0% |
| Crème fraîche | 2L tub | £8.00 | 0% |
| Blue roll | 6 rolls | £14.40 | 20% |
Step 1: read the line, not the total
Look at the pack column first. "2 x 5kg" means one case holds 10kg. The £47.00 is for the case, not per bag.
This is where most hand costing goes wrong. People divide by 5 instead of 10. The dish looks twice as expensive, or half, depending on the mistake.
Step 2: turn the pack price into price per kg
Divide the pack price by the total weight in the pack.
- Chicken thigh: £47.00 ÷ 10kg = £4.70 per kg
- Leeks: £9.50 ÷ 5kg = £1.90 per kg
- Crème fraîche: £8.00 ÷ 2L = £4.00 per litre
Step 3: take VAT out
Most food in the UK is zero-rated, so the food lines carry no VAT. Some lines do: cleaning stock, soft drinks, crisps, confectionery. If you are VAT registered, you claim that VAT back. So always cost from the price before VAT.
The blue roll is not in the dish anyway. But on a drinks invoice, the 20% matters on every line.
Step 4: fix the price for what you actually use
Leeks lose their roots and dark tops. Say 70% of the box ends up on plates. The usable price is £1.90 ÷ 0.70 = £2.71 per kg. The chicken is already trimmed, so it stays at £4.70. The yield and waste guide goes into this properly.
Step 5: cost the plate
| Ingredient | Portion | Price | Cost |
|---|---|---|---|
| Chicken thigh | 220g | £4.70/kg | £1.03 |
| Leeks (usable) | 150g | £2.71/kg | £0.41 |
| Crème fraîche | 50ml | £4.00/L | £0.20 |
| Rest of plate (potatoes, butter, herbs) | from other invoices | £2.10 | |
| Plate cost | £3.74 |
Menu price is £16 including VAT. Ex-VAT, that is £16 ÷ 1.2 = £13.33. GP is (£13.33 − £3.74) ÷ £13.33 = 71.9%. Food cost is 28.1%.
Now the old sheet. It still had chicken at £3.90 a kilo. That made the plate £3.56 and the GP 73.3%. A 1.4 point drop from one invoice line, and nobody noticed. The GP and VAT guide explains why the ex-VAT price is the one that counts.
Step 6: find every recipe that uses it
This is the step everyone skips. Chicken thigh is not only in this dish. It is in the staff curry, the Sunday special and a sharing plate. Each of them just got more expensive too.
By hand, you search the sheet for every recipe with that ingredient and update each one. With six invoices a week, that is an evening.
Common mistakes when costing from an invoice
- Dividing by the wrong pack size. "12 x 1L" is 12 litres, not 1.
- Catch-weight lines. Meat and fish are often billed on actual weight. The case says 5kg, the line says 5.32kg. Use the line.
- Costing from VAT-inclusive prices. It makes standard-rated items look 20% dearer than they are.
- Ignoring credits. A credit note for short delivery changes the real price paid.
- Using the price you remember. Memory is always a few weeks old.
- Updating one recipe and not the rest. The price changed for every dish using that ingredient.
What automatic food cost from supplier invoices means
Everything above is the method. Mise n' Price does the same steps for you, with your phone.
You photograph the invoice. It reads the lines, Hebrew or English. The prices land on your ingredients, per kg or per litre. Every recipe using them shows the new cost per portion and GP. Yield, waste, sub-recipes and VAT are handled the same way as above.
That is the whole pitch. One invoice in, every dish that uses it costed again.
Be honest about the photo read
A photo of a crumpled invoice is not a clean document. Invoice scanning, restaurant OCR, whatever you call it, will sometimes read a line wrong. A 1 becomes a 7. A pack size gets missed. A smudge on the till roll hides a decimal point.
So check it. Glance down the lines it read. Compare two or three prices against the paper, especially the big ones: meat, fish, dairy. If a dish suddenly jumps 40% in cost, the invoice read is the first place to look.
It still takes a minute instead of an evening. But a minute of checking is part of the job, the same as checking the delivery itself.
What to do this week
- Pick your best-selling dish.
- Pull the last invoice for its main ingredient.
- Work out price per kg, ex-VAT, after yield, like above.
- Compare it with the price in your sheet.
- Put the plate cost and menu price into the free GP calculator and see where you stand.
If the gap is big, do the next dish. Most UK kitchens aim for 65–72% GP on food. If you want the full method from scratch, read how to cost a dish. If you are weighing up the sheet against an app, there is an honest comparison in recipe costing spreadsheet vs software.
Mise n' Price is in closed beta and free until 13 December.