What is prime cost? The one number that decides if you make money.

There are dozens of numbers you could track in a venue. There is one you cannot afford to get wrong. Prime cost. Get this right and the rest tends to follow. Get it wrong and you can have a packed room every night and still go broke.

What prime cost actually is

Prime cost is the two biggest controllable costs in your venue added together. Cost of goods sold, which is the food and drink you buy. And total labour, which is wages plus all the on-costs that come with them. You add the two and express the result as a percentage of revenue.

Everything else is mostly fixed. Rent does not move with how busy you are. Insurance does not care if you had a big Saturday. But COGS and labour move every single day, with every decision you make. That is why they are called prime. They are the costs you actually drive.

The benchmarks for an Australian venue

There is no single right number, because a wine bar and a high-volume cafe have very different shapes. But across most Australian hospitality, the bands are clear. This is the quick read on where you sit.

If you sit above 65% and have not looked closely, do not panic. It usually means there is real money sitting in the gap, waiting to be found. The venues that fix this are not cutting quality. They are cutting waste they did not know was there.

The mistake that costs the most: checking it monthly

Most operators see their prime cost once a month, when the accountant sends the numbers, three weeks after the month has ended. By then it is history. You cannot fix a Tuesday that happened five weeks ago.

The best operators check it weekly. Some check the moving parts daily. The reason is simple. A roster that is 4 points too heavy costs you a little every shift. Catch it on Tuesday and you save the rest of the week. Catch it at month end and you have already paid for it twenty times over. Weekly is the rhythm. It turns a post-mortem into a steering wheel.

Where prime cost quietly leaks

When prime cost drifts up, it is rarely one big thing. It is five small things, each costing a bit, adding up to real money. These are the usual suspects.

• Over-rostering. An extra body on a quiet shift, repeated all week, is thousands a month. This is the single biggest controllable leak in most venues.
• Portion drift. The kitchen gets generous. A few extra grams per plate, multiplied by every cover, walks straight off your margin.
• Supplier creep. Prices nudge up 3% here, 5% there, and nobody re-prices the menu. Your costs rose. Your prices did not.
• Menu pricing lag. A dish costed two years ago is being sold at two-years-ago prices on today-priced ingredients.
• Waste and theft. Spoilage, comps, over-pours, and the till that does not quite reconcile. Small per incident. Constant in total.

How to use prime cost from this week

Start simple. Pull last week's revenue, your COGS for the week, and your total labour including super and on-costs. Add the two costs, divide by revenue, and you have your number. Do not chase perfect. A rough weekly read beats a perfect monthly one every time.

Then do it again next week. The number on its own is useful. The trend is where the money is. A prime cost that creeps from 61 to 64 over a month is telling you something before it becomes a problem you can feel in the bank account.

If you want to run the maths properly, the Prime Cost Calculator does it for you, with the AU benchmarks built in. And the Labour Cost Calculator will show you the true labour figure, on-costs and all, because that is where most people undercount.