Tools

Drinks GP Calculator: Cost Per Serve, Measures and Margin

Bottle price is not serve cost. This calculator turns a bottle into servings at your house measure, takes the VAT off the selling price, and gives you the GP on the drink as you actually pour it.

Alex Riesenkampff

August 21, 2026 · 7 min read · Markdown

A bottle price tells you almost nothing about the margin on a drink, because the number that matters is the cost of one serve, and that depends on a measure you chose once and applied to the whole bar. A £16 bottle of gin costs 57p a serve at 25ml and 80p at 35ml. On a £4.20 measure of gin, that is the difference between 83.7% GP and 77.1%.

That figure assumes the measure in the glass is the measure on the price list. Bar losses are rarely one dramatic event; they are a couple of millilitres, several hundred times a week. Here is what that is worth.

Knowing the cost per serve is only half of it. The other half is what the drink is worth to the person buying it, and that number rarely lives on your price list.

At a bar and café in Berlin Prenzlauer Berg, Super44 compared their cocktail prices against nearby venues and found comparable pours selling at €15 to €18 while they charged €10. They raised premium cocktails to €12. The owner confirmed the change, and the projected upside was over €1,200 a month, from stock they were already pouring.

That is the pattern worth noticing. The pour cost was never the problem on that bar. The price was, and nothing in a GP calculator can tell you so, because a calculator only knows the numbers you already have.

The measure is a margin decision made once

Gin, rum, vodka and whisky must be sold for consumption on licensed premises in 25ml or 35ml, or multiples. The 35ml option was not always there: it was added by the Weights and Measures (Intoxicating Liquor) Order 1994, which amended the 1988 Order to provide a second metric quantity.

A venue picks one and displays it. That makes the measure a house-wide policy with a house-wide margin consequence, rather than something you can tune drink by drink. Moving from 25ml to 35ml is a 40% increase in the spirit going into every glass, and unless the price moves with it, the GP on the entire spirits list drops together.

Neither measure is the right answer. A 35ml house measure is a genuine proposition in some markets and reads as generous. The mistake is running 35ml on a price list that was built around 25ml, which is a thing that happens quietly when a venue changes hands.

Wine by the glass, same arithmetic

Put 750 in the bottle field and your pour in the measure field. A 750ml bottle gives six 125ml glasses and three at 250ml, both of which divide exactly.

175ml does not, and the calculator will not warn you. It reports 4.3 serves from a 750ml bottle, and a bar gets four glasses and 50ml of residue. So enter the volume you can actually sell rather than the volume on the label: 700ml for a bottle poured at 175ml. On an £8 glass that correction is the difference between a reported 44% GP and a real 40%, and it applies to every bottle on the list.

What a good drinks GP looks like, and who gets to have one

The bands quoted at you for spirits and wine, usually somewhere in the seventies, have no published source we could find. We looked: BBPA, UKHospitality and the British Institute of Innkeeping publish a great deal, but not a target GP by drink category. The figures come from software companies and wholesalers.

The closest thing to a real benchmark comes from UKHospitality and Christie & Co, whose report is built from members' actual profit and loss accounts across 4,791 managed outlets rather than from estimates. On wet sales it found the highest margins in Nightclubs at 72.7% and Casual Dining at 72.1%, and it explains the nightclub figure by sales mix rather than by skill, noting that "higher margin spirits and mixers are a popular drink of choice in these establishments."

The more useful finding is about who you are, not what you sell. The same report puts wet-sales GP at 68.9% for estates on mainly commercial leases against 61.2% for those on mainly tied leases, a gap it states as 7.8 percentage points. If you are tied, much of the distance between you and the figure on a wholesaler's website is your lease, not your bar. The report does ask for caution here, because its tied-lease sample is small.

Two caveats the report makes itself, and you should carry: the data covers the six months to 31 December 2021, and margins that period were affected by the temporary hospitality VAT reduction that has since ended.

What this does not include

This is theoretical GP: what the drink would make if every pour were exact and every sale rang through the till. Your actual figure will be lower, and the distance between the two is the number worth watching. It is made up of free pour, spillage, staff drinks, comps, and stock that leaves without a sale.

The calculation still earns its place, because you cannot size that gap without the theoretical side of it. Run it across your top twenty lines, compare against what the till and the stocktake say, and the difference tells you where to look.

For the plain version of this sum on any single line, use the GP calculator. Draught has its own problem, which is that a keg does not contain as many saleable pints as it contains beer: beer GP calculator. And if you are working the other way, from a target margin to a price, how to price a menu item covers the contribution-margin approach that suits a drinks list better than a flat percentage does.