How to take inventory with a scale

Last updated: 26 June 2026

Most pubs lose money every single week without realising it—not through theft, but through measurement error, over-pouring, and forgotten wastage that hides in the numbers. A 1% stock loss on wet sales quietly costs a typical pub £3,000–£5,000 a year, and most operators never spot it because they’re counting wrong. The truth is simpler than you think: a set of scales and a dipstick, used consistently, will tell you more about your profit than any spreadsheet ever will. This guide shows you exactly how to take inventory with a scale—the same method I’ve used to claw back 1–2 gross profit points within a couple of months at my own pub.

Why a scale matters more than you think

Here’s what most pubs get wrong: they focus on the total stock value and miss the actual leak. You can have £4,000 of stock on the shelves and still be losing £200 a week because you’re not measuring the rate of depletion against what was sold. A scale doesn’t give you a headline number—it gives you a variance. That’s the number that matters.

The most effective way to spot pub stock losses is to weigh open spirit bottles and measure cask depletion weekly against till sales, because this catches the three places most losses hide: over-pouring on spirits, cellar waste from poor line temperature, and forgotten spillage.

At my own pub I was running stock on a tangle of spreadsheets and still losing track of partial kegs and spirit measures. The variance was always “about right”—which meant I had no idea what was actually happening. 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. Within two months, I’d caught nearly £500 in recurring weekly losses that had been invisible before.

The problem isn’t your scales—it’s that most operators count monthly or less, so the variance gets buried under two or three weeks of noise. Weekly counts are fast and they show you the trend. That’s what stops the bleed.

What equipment you actually need

You don’t need fancy kit. You need consistent kit. Here’s what works:

• One set of digital kitchen scales (±5g accuracy) — costs £15–30, sits on a shelf in the cellar or stockroom, stays there. Don’t move it between counts.
• A plastic dipstick — comes with most new casks from the brewery; if you don’t have one, get one from your supplier or make a simple marked ruler. Costs nothing.
• A notebook or spreadsheet — record the weight of each open bottle and the cask depth the same day, every week, same time. Tuesday morning works well.
• A calculator — to work out the difference between last week’s weight and this week’s weight, then multiply by the number of days.

Do you really need special equipment? No. Do you need reliable equipment that doesn’t move and doesn’t change? Yes. Most pubs have scales somewhere. Find them, calibrate them once, and use them every week.

The StockTap pub stock app automates the recording and variance calculation for you—you still weigh and measure by hand, but the maths is built in—but a spreadsheet works fine if you’re disciplined. The tool doesn’t matter. The habit matters.

Step-by-step method for weighing spirits

Most losses on spirits come from over-pouring. A free-poured 25ml spirit measure is often 32–35ml in real pubs, and that adds up fast. Weekly weighing catches this.

The process

1. Pick a day and time. Same day every week, same time. Tuesday 10am works well. Don’t skip weeks.
2. Zero the scales. Do this before every bottle—put the bottle on, then press the tare button.
3. Weigh each open bottle of spirits. Write down the exact weight. Spirits weigh roughly 0.95g per ml, so 750ml of vodka should weigh about 710g full, 375g at half, and so on. The weight tells you the volume.
4. Compare to last week’s weight. If a bottle of vodka was 620g last week and is 580g this week, you’ve used 40g—roughly 42ml. You sold (from the till) 35 measures at 25ml each = 875ml. The gap is your loss.
5. Record the variance. Multiply the weekly loss by 52 and you have an annual loss number. Most pubs are surprised by this figure.

Weighing open bottles catches the losses that sit invisible in over-pouring, and a weekly routine makes the trend impossible to miss.

One detail that matters: weigh the bottle on the same scales every time, in the same location, at roughly the same temperature. Spirits expand and contract slightly with temperature, so a 1–2g variance week-to-week is noise, but a 20g drop over seven days is real.

How to measure cask and keg stock

Draught beer losses hide in three places: bad line cleaning waste, cellar temperature drift, and partial kegs you’ve forgotten about. A dipstick solves two of these instantly.

Using a dipstick on casks

A dipstick is a marked plastic rod that shows the depth of beer left in a cask. It’s not fancy—it’s just measurement.

1. Push the dipstick through the shive (the hole in the top of the cask) vertically until it touches the bottom.
2. Mark where the surface of the beer sits on the stick. Most commercial sticks have markings for pints remaining (e.g., 72 pints, 36 pints, etc.).
3. Write down the number. Record which cask, the depth in pints (or litres), and the date.
4. Calculate the weekly depletion rate. If a cask dropped from 60 pints to 45 pints in seven days, you’ve used 15 pints. Check the till sales for that beer line. If till shows 18 pints sold, you’ve got a 3-pint loss—likely line waste or temperature-related shrinkage.

A dipstick reveals cask depletion rate in minutes, and comparing the dip to till sales shows whether your line is clean or wasting beer to temperature and pressure problems.

Partial kegs are where most pub operators lose focus. A half-full keg of lager sitting in the corner gets forgotten, and you end up with three weeks of barely-tracked depletion. Dip every keg, even the partial ones. Write them down. You’ll find beer you’d completely forgotten about.

Reconciling your counts against till data

The reconciliation is where the real insight lives. Your scales and dipstick give you physical stock. Your till gives you sales. The gap is your loss—or your gain, if you’re lucky.

The weekly reconciliation routine

Do this the same day you count:

• Extract till sales for the past seven days — by product line (Guinness, Stella, Vodka, etc.). Most EPOS systems have this report built in.
• Convert till sales to the same units as your physical count — pints to litres, or measures to ml.
• Calculate the expected depletion. Till says you sold 120 pints of bitter. Physical stock shows only 110 pints of depletion. You’ve got a 10-pint variance.
• Record the percentage variance. Divide loss by sales: 10 ÷ 120 = 8.3%. Most pubs should be under 3%. Anything over 5% needs immediate investigation.

Do this the same day you count. Don’t let a week pass before you reconcile—by then you’ve forgotten what you saw, and the causes are harder to trace.

At my pub, Tuesday morning count at 10am, Tuesday afternoon reconciliation by 3pm. Takes 30 minutes total. I know by Wednesday morning whether the cellar is clean or leaking. That speed makes a difference—you can fix a problem before it costs you a month.

Common mistakes and how to avoid them

Mistake 1: Counting inconsistently

Counting one week, skipping two weeks, then counting again tells you almost nothing. A weekly count takes 20 minutes. Do it every week, same time, same day. That’s not negotiable if you want a number you can trust.

Mistake 2: Forgetting to account for deliveries and wastage

If you took a delivery of spirits on Thursday, your Friday count will show a big jump. Record deliveries on the day they arrive. Record wastage (broken bottles, spillage, staff drinks) in a separate log. Your variance calculation should be: (Opening Stock + Deliveries − Closing Stock − Recorded Wastage) ÷ Till Sales.

Mistake 3: Trusting the brewery’s stocktaker to catch everything

The brewery stocktaker comes quarterly or half-yearly. By then, you’re blind for three months. A weekly count is your stocktake. You’re not checking everything—you’re checking the trend. The brewery stocktaker will tell you if you’re massively out, but they won’t tell you that you’re bleeding 2% every week, because they only see a snapshot.

Mistake 4: Using scales that move or aren’t calibrated

If your scales live on different shelves, or you borrow someone else’s scales, your numbers won’t be comparable week-to-week. Buy one cheap set of scales, put them in the cellar, and don’t move them. Calibrate them once using a known weight (a 1kg bag of sugar, for example) and then leave them alone.

Spirits hide losses in over-pouring, draught hides it in poor cellar temperature and bad line cleaning waste, and most stock ‘theft’ is actually measurement error and forgotten wastage. Weigh open spirit bottles, dip every cask and partial keg, and reconcile against till data the same day. That’s the method that works.