You can run a busy cafe all day and still lose money, and when that happens the leak is almost always on the plate. A dish that costs more to make than its price allows loses a little on every serve, hundreds of times a week, and nobody notices. A food cost calculator puts a real number on what each item costs, so you find the leak before it starts.
The formula is simple. The work is in costing on yielded weight, turning a target into a price, and keeping the numbers honest once you're trading.
The food cost formula, in one line
A food cost calculator rests on one calculation. Food cost percentage is the cost of the ingredients in a dish divided by its sell price ex GST, times 100. The 10% GST in a menu price goes to the ATO, so divide the menu price by 1.1 first.
| Food cost percentage | (ingredient cost of the dish ÷ sell price ex GST) × 100 |
The result is the share of the price ex GST that goes on ingredients. A 30% food cost means 30 cents in every dollar goes on ingredients, leaving 70 cents for labour, rent, overheads and profit. Lower is better, but only if the number is honest, and that's where the detail comes in.
Cost on what reaches the plate, not what you bought
This step decides whether the calculator helps you or flatters you. You rarely sell everything you buy. Trim, peel, wastage and cooking loss all mean the usable quantity is less than the purchase quantity, so each usable gram costs more than the invoice suggests.
Cost a dish on what you paid at the door and the food cost looks lower than it really is, so your margin is thinner than the number says. Cost it on the yielded, usable weight and the calculator tells the truth.
A kilo of avocados is not a kilo of usable flesh. Once you remove the skin and stone you might keep around 70%, so a kilo bought at $8 costs closer to $11.40 per usable kilo. The same goes for trimmed meat, drained tins and anything that loses weight in prep or cooking.
A worked example: costing Smashed Avocado on Toast
Take a cafe staple and cost it properly, ingredient by ingredient, on yielded weight, small things included.
| Ingredient | Cost per serve |
| Avocado (yielded) | $1.70 |
| Sourdough, two slices | $0.80 |
| Feta | $0.60 |
| Lemon, oil, salt, chilli | $0.25 |
| Garnish and micro herbs | $0.15 |
| Total dish cost | $3.50 |
Sell it at $12 on the menu, $10.91 ex GST, and the food cost is 3.50 divided by 10.91, about 32%. That's inside a healthy range, so the dish earns its place. Now leave out the oil, lemon and garnish, the bits a rushed costing usually drops. You'd have costed it at $3.10 and read 28%, understating the cost of every serve. Multiply small misses like that across a week of covers and you've found where menus quietly underperform.
Working the calculator backwards to set a price
Once you can cost a dish, you can run the same calculator in reverse: start from the food cost you want and solve for the price. That's how you price to a margin instead of guessing a number and hoping.
| Sell price ex GST | dish cost ÷ target food cost (as a decimal) |
| Menu price | sell price ex GST × 1.1 |
Take the $3.50 dish and a 30% target. Divide 3.50 by 0.30 and you get about $11.67 ex GST. Add 10% GST for $12.83, which you round to a sensible menu price such as $12.90. Want a tighter 28% food cost? Divide 3.50 by 0.28 for $12.50 ex GST, or $13.75 on the menu. The calculator gives you the price the margin needs. Where it sits against your market is your call. For the full method, see our guide on how to price a cafe menu.
Food cost is worked on the price ex GST, because the GST your customer pays goes to the ATO, not to the cafe. Add 10% only at the end, for the menu price. Check the ATO's GST rules for food, because some items are treated differently for dine in and takeaway.
From one dish to the whole menu
One dish at 32% doesn't make a healthy cafe. The whole menu does. Some items run lower, coffee and drinks especially, and some food runs higher. What matters is where the blended food cost lands across the mix you actually sell.
So cost every item, not just the obvious ones. Run the calculator across the whole menu and you'll see which dishes carry the margin, which drag on it, and where a small reprice or portion tweak lifts the blended number. Pair this with the target range in our guide on what food cost percentage a cafe should aim for, and the method in how to cost a cafe menu.
Do not forget to cost the coffee
Coffee is where a cafe makes much of its money, and it's the item owners most often cost by feel. The same formula applies, and the small parts matter just as much as they do on a plate.
Cost a Flat White and you count the coffee dose, the milk, the cup (or the washing cost for a ceramic), the lid and the sugar. One serve looks like cents, which is exactly why it gets waved through. But coffee sells in the hundreds a day, so a few cents of uncosted milk or a heavy dose is real money by the end of the week.
| Component | Cost per serve |
| Coffee dose (yielded from the bag) | $0.44 |
| Milk, averaged across the milks customers choose | $0.74 |
| Cup and lid | $0.15 |
| Syrups and extra shots, averaged across orders | $0.13 |
| Total drink cost | $1.46 |
Sell it at $5.50, $5.00 ex GST, and the food cost is about 29%, a 71% GP. Plant milks are what push it up, which is why many cafes charge extra for them. But dose heavier or pour milk without measuring and that number climbs faster than you'd expect. Cost the coffee with the same calculator you use for food and your highest margin line stays that way.
A calculator is only as good as its last update
A one off calculation goes out of date. Supplier prices move, portions creep, and a menu costed once at opening slowly drifts. A dish that read 29% in summer can be well past target by winter with no change to the recipe, just because the ingredients cost more.
A spreadsheet does the maths for one dish, but keeping it current across a whole menu means editing formulas by hand every time a price changes. Once service takes over, that almost never happens. A live calculator updates when a price or portion moves, so the numbers stay honest without the manual upkeep.
HospoSure costs every dish on yielded weight, recosts every dish that uses an ingredient when you update its supplier price, and shows the food cost percentage and margin on each item as you build the menu. Start from a pre-costed recipe library and adjust, or build your own.
Cost your menuUsing a food cost calculator well
An owner who costs their menu properly:
- Uses the formula ingredient cost divided by sell price ex GST, times 100, on every dish.
- Costs on yielded weight, not purchase weight, so the number tells the truth.
- Includes the small ingredients, the oil, garnish and milk that add up.
- Works the calculator backwards to set prices from a target margin, not a guess.
- Costs the whole menu, knowing the blended food cost is what matters.
- Keeps it live, recalculating as prices and portions move.
Cost honestly, price to a target and keep the numbers current, and you'll know dish by dish where your margin is made and where it leaks.