Beer keg measuring tools for pub stocktaking

Last updated: 29 June 2026

Most publicans have no idea how much beer they’re actually losing week to week—and it’s not because they’re not counting kegs, it’s because they’re counting them wrong. A 1% stock loss on wet sales quietly costs a typical pub £3,000–£5,000 a year, and a proper weekly line check using the right measuring tool catches it before it becomes a silent profit drain. The difference between a spreadsheet guess and a measured number is the difference between accepting wastage and controlling it.

If you’re running a tied pub or managing someone else’s cellar, you’ve probably inherited whatever measuring system the previous licensee left behind—which usually means a old dipstick jammed in a corner, a set of scales that haven’t been calibrated since 2019, and a vague idea that “the brewery will sort it out at the end of the quarter.” That’s how I started. This article tells you exactly what tools actually work, how to use them without adding an hour to your weekly count, and why a beer keg measuring tool is the first thing you need before you trust any stock figure.

Why a proper beer keg measuring tool matters more than you think

Spirits hide losses in over-pouring (a free-poured 25ml is often 32–35ml), draught hides it in poor cellar temperature and bad line cleaning waste, and most stock ‘theft’ is actually measurement error and forgotten wastage. That’s the bit most licensees don’t grasp until they’ve run the numbers properly for the first time.

The number that actually matters is wet gross profit by line, not a single headline stock figure. Your EPOS tells you what sold. But it doesn’t tell you whether you made money on it—not until you reconcile it against what you actually measured in the cellar. That gap is where your margin lives or dies.

At my own pub I was running stock on a tangle of spreadsheets and still losing track of partial kegs and spirit measures. I built a simple count routine around a dipstick and a set of scales, and the weekly variance went from guesswork to a number I could trust within a fortnight. Once I started reconciling that measured stock against the till the same day, I could see which lines were bleeding money. Within two months, I clawed back nearly 2 GP points—and that wasn’t from plugging theft, it was from fixing how we were actually pouring and cleaning lines.

A StockTap pub stock app records those numbers for you, but the numbers are only as good as the tool you used to measure them. That’s why you start with the equipment.

The three measuring tools you actually need

1. A quality dipstick

This is your primary tool. A good dipstick measures the depth of liquid in a keg from top to bottom and translates that depth into a volume—usually in pints or litres. Most come with a conversion chart printed on the side. You’re looking for one that’s:

• Stainless steel (won’t rust, won’t skew readings from moisture)
• Clearly marked with depth increments and volume conversions
• Long enough to reach the bottom of a full keg without strain
• Durable enough that the markings don’t fade after a year of wet cellar use

Avoid plastic dipsticks—they warp, markings wear off, and you’ll be replacing them every 18 months. A stainless steel dipstick costs £15–£25 and lasts years. It’s the best £20 you’ll spend on cellar equipment.

2. Digital scales with at least 5kg capacity

You need these for open bottles—spirits, wine, cordials, and any partial kegs you’re actively using. Weigh them weekly at the same time. The difference in weight between weeks tells you what you’ve sold (weight loss equals volume sold, accounting for density). Digital scales must be:

• Accurate to at least 10g
• Battery-powered with a clear LCD display
• Calibrated at the start of every month (most have a calibration function)

You’re not looking for laboratory precision—you’re looking for consistency. The same scales, used the same way, every week. That’s what gives you a trend you can trust.

3. A recording method you’ll actually use weekly

This is where most licensees fail. They measure everything correctly, then write it on the back of a receipt, forget to photograph it, and can’t find it when they need it. SmartPubTools built a dedicated stocktaking screen into StockTap specifically because spreadsheets are where stock records go to die.

Whatever you use—spreadsheet, dedicated app, or notebook—it must be:

• Completed the same day, every week (Monday morning, Friday afternoon, pick one)
• Searchable when you need to find last week’s number
• Linked to your till data so you can spot the gap between what was sold and what was counted

How to use a dipstick on casks and kegs

The most effective way to measure a keg is to insert the dipstick vertically, straight down to the bottom, and read the liquid level where it sits at the surface of the beer. This gives you the depth, which you then convert using the printed scale on the stick.

For casks (usually real ale): Insert the dipstick through the keystone or shive hole at the top. Push gently until you feel it touch the bottom. Read where the liquid line sits on the stick. Write down the depth (usually in inches) and convert it using the chart printed on the stick. Most casks will show a conversion to pints or gallons. If your stick doesn’t have a conversion chart, take a photo of the depth and convert it later using a standard cask volume calculator.

For kegs (usually lager, cider, or stout): The approach is identical. You’re measuring the depth of liquid from the top surface downward. The only difference is that kegs are pressurised, so never depressurise a keg just to measure it—that wastes product and throws off your readings. Measure through the top without releasing pressure. If your keg is too pressurised to insert a dipstick safely, something else is wrong with your cellar setup (usually temperature or line pressure).

Record the depth AND the volume every time. The depth tells you something is changing; the volume tells you how much. Do both, every week, in the same order, at the same time of day. Consistency beats accuracy when you’re trying to spot a trend.

When and why to weigh open bottles

Every spirit bottle currently in use behind the bar or in the cellar should be weighed once a week. Same day, same scales, same position on those scales. A full 70cl bottle of 40% ABV spirit weighs roughly 890g. If it weighed 850g last week and 760g this week, you’ve sold 90g of product (roughly 3 measures at 25ml standard).

Why this matters: Over-pouring. A free-poured 25ml measure is often 32–35ml in reality. If your scales show you’ve poured 150ml of vodka this week and your till shows only 4 measures sold, you’ve got a pouring problem, not a theft problem.

Weigh:

• Every open spirit bottle
• Wine (by the glass) once a week
• Cordials and juices (once a week is fine)
• Any partial keg you’re actively serving from

Don’t weigh full, unopened bottles—they’re already inventory control through the till. Start weighing the moment you open a bottle, and keep weighing every week until it’s empty.

Common mistakes that kill accuracy

Measuring at different times of day

Cellar temperature changes throughout the day. Beer contracts and expands slightly with temperature. If you measure Monday at 7am when the cellar is cold, and Wednesday at 2pm when it’s warmed up, your readings will be inconsistent even if nothing’s changed. Always measure at the same time of day. Friday after opening the cellar works well; so does Tuesday morning. Pick one and stick to it.

Not calibrating scales monthly

A digital scale that’s off by 20g doesn’t sound like much, but over a month it adds up. Calibrate using a known weight (many scales come with a calibration weight, or use a coin—a UK 1p coin weighs exactly 3.56g). Do this once a month without fail.

Relying on the brewery’s quarterly stocktake

The brewery’s stocktake is their audit of what they’ve supplied. It’s not your measure of what you’ve sold or lost. By the time the quarterly audit happens, you’re already three months into a problem. A proper weekly line check finds the issue in week one.

Forgetting partial kegs exist

This is the big one. A keg that’s been on tap for two weeks is a partial keg. It’s still inventory. Measure it. Every licensee I know has found a forgotten partial keg in the corner that’s been sitting there for a month, still on the manifest, still eating margin. Measure every keg with beer in it, full or not.

Building a weekly routine that takes 15 minutes

Here’s what my routine looks like, and it works:

Monday, 10:30am (before service):

• Check cellar temperature (should be 50–52°F for lager, 52–55°F for ales)
• Measure every active keg with the dipstick (5–8 minutes for a typical pub)
• Weigh every open bottle and note the weight (3–4 minutes)
• Record everything in StockTap (2 minutes)

Total time: 12–15 minutes. Then you’re done until next week.

What you do with the numbers: That same morning, pull your till report for the previous week. Compare what you sold (according to till) against what you counted (according to dipstick and scales). The gap is your variance. If variance is consistently over 3%, something’s wrong—over-pouring, temperature creep, poor cleaning waste, or a real loss. Investigate that line specifically.

Most pubs that move from a messy spreadsheet to a disciplined count claw back 1–2 GP points within a couple of months, purely from visibility. You don’t need to be perfect; you just need to be consistent and honest about what the numbers say.