Sep 10, 2026
Last Updated: September 10, 2026
The 80/20 rule in stock is the principle that roughly 80% of your sales and profit come from about 20% of your stock lines (investopedia.com). It is a working method for deciding where your cash, shelf space and attention should go, not a mathematical law. At Swallow Drinks, we have spent over 40 years supplying the on-trade across Birmingham and the surrounding areas, and the bars that run tight stock control almost always apply this thinking without calling it anything.
The idea traces back to Vilfredo Pareto, the Italian economist who observed that a minority of causes tends to produce a majority of effects (britannica.com). In a bar, that shows up fast: a handful of spirits, a core draught line-up and two or three wine labels do the heavy lifting, while the rest of the back bar gathers dust.
The Pareto Principle states that a small number of inputs usually drive a large share of outputs. Applied to stock, it means a minority of product lines generate the majority of revenue and margin.
The exact split rarely lands on 80 and 20. Yours might be 70/15 or 85/25, and it shifts with the seasons. The ratio is a starting point for asking better questions, not a target to hit.
Cash tied up in slow-moving bottles is cash not funding your best sellers. Stock that sits also takes up shelf space, counts towards your carrying costs and eventually becomes dead stock written off at a loss.
Prioritising your top lines improves stock turnover, reduces overstocking and cuts the odds of a stockout on the one product a customer actually came in for (peer-reviewed research).
ABC analysis for bars is a stock classification method that sorts every product line into three tiers by value. Class A items are your highest-value lines, Class B sits in the middle, and Class C covers the long tail. It is the practical engine behind the 80/20 rule.
Most venues find that Class A holds a small share of stock keeping units but the bulk of sales value. Class C is the opposite: lots of lines, little revenue. That mismatch is where stock control usually goes wrong.
| Class | Share of Lines | Share of Sales Value | How to Manage |
|---|---|---|---|
| A | Small | Largest | Frequent counts, tight safety stock |
| B | Moderate | Moderate | Scheduled review, standard reorder |
| C | Largest | Smallest | Order to demand, minimal holding |
The discipline is refusing to treat every line as equally important. A bottle that sells twice a month should not get the same attention as one that empties nightly.
You can run a full 80/20 split on a printed stock sheet or a basic spreadsheet in under an hour. No software required, which matters if you are a small independent bar watching every pound. Most guides assume you have an enterprise EPOS with a reporting suite; the manual workflow below is built for venues running a till and a clipboard.
Suppose a gastropub carries 120 lines and turns over a set period in which total gross profit reaches a round figure. When you rank by profit, a common pattern is that the top 20 or so lines, house spirits, the two best-selling draught lines, a core mixer and three wine labels, account for the large majority of that profit. The remaining 100 lines split the rest between them. The exact split rarely lands on 80 and 20; yours might be 70/15 or 85/25. The ratio is a starting point for asking better questions, not a target to hit.
A simple layout works: column A for the product name, column B for cost price, column C for retail price, column D for units sold in the period, column E for gross profit per line (units sold multiplied by the difference between C and B), and column F for a running total. Sort by column E descending, then add a cumulative percentage column so you can see exactly where the 80% line falls. Freeze the top row, and you have a reusable template you can refresh each quarter by pasting in new sales figures.
A single split is a snapshot. Seasonal demand moves it, sometimes sharply. Rather than recalculating from scratch every time, keep the spreadsheet and re-run it on a rolling basis, monthly in busy periods, quarterly when trading is steady. Compare the current ranking against the previous one and flag any line that has moved more than a tier. A summer line that climbs into Class A in June and falls back by October is normal; a line that drifts down two tiers over two quarters is a candidate for delisting.
If you would rather not build the template yourself, a supplier who knows your menu can help you read the output and turn it into an order pattern. Swallow Drinks has supplied the on-trade for over 40 years, and trade customers can register for a trade account to order online and keep the reorder cycle simple.
Waste falls fastest when you stop spreading effort evenly. To reduce drink waste, concentrate your controls on the lines that carry the most value, because that is where the money leaks.
Start with portion control on Class A spirits and draught. A few millimetres over-poured on your busiest product costs more across a month than a whole case of a slow line. Train staff on measured pours and check them.
Then review your Class C lines honestly. If a niche bottle has been open for months, it is a write-off waiting to happen. Either move it with a menu feature or stop stocking it.
Regular stocktakes on your top lines catch shrinkage early. A weekly count on Class A takes minutes and gives you a number you can act on.
Good bar stock management best practices make the 80/20 rule stick rather than fade after one good month. The principle only pays off when it is built into your routine.
Set par levels by class. Class A lines get a higher safety stock and more frequent replenishment; Class C lines get ordered to demand. This keeps capital out of slow stock and available for the lines that earn.
Review your supplier relationship too. A wholesaler who understands your menu can help you spot which lines to push and which to drop. Swallow Drinks works with independent pubs, gastropubs and hotel groups across the region on exactly that, and trade customers can register for a trade account to order online.
Most guides treat the 80/20 rule as a one-off exercise and skip the mistakes that undo it. The failures below are the ones that actually cost venues money, and each has a fix.
The split is a snapshot of your current trading, and it moves. A split calculated in a quiet month will under-order your summer lines and leave you short on a Saturday. The fix is a rolling review: re-run the calculation when your trading pattern changes, and keep the previous ranking so you can see which lines are climbing or falling. A line that moves up a tier deserves a higher par level; one that drops two tiers deserves a hard look.
Cutting every slow line looks efficient on paper and damages the business in practice. Some Class C items are the reason a customer chooses you over the venue down the road, a specific bitter, a niche gin, a wine a regular always orders. The skill is telling the two apart. Ask whether the line supports a menu, a cocktail list or a loyal customer; if it does, keep a small quantity and order to demand rather than delisting it. If it does not, it is dead weight.
The 80/20 rule tells you what matters now. Forecasting tells you what will matter next month. Used together, they stop you over-ordering a fading line and under-ordering a rising one. A simple approach is to compare the current ranking against the same period last year and adjust par levels for any line with a clear seasonal pattern. Without that step, you are always managing last season's demand.
Bulk buying a Class B line because the price looked sharp ties up cash and shelf space that your Class A lines need more. A discount on a slow line is not a saving; it is a longer holding period and a higher chance of write-off. Before accepting any bulk offer, check where the line sits in your ranking and how quickly it turns.
The opposite mistake is applying the same counting and reorder discipline to every line. Class A lines need frequent counts and tight safety stock; Class C lines need minimal holding and order-to-demand. Treating them the same wastes effort on the long tail and leaves your best sellers under-watched.
If you want help turning the ranking into a workable order pattern, a supplier who understands your menu can spot which lines to push and which to drop. Swallow Drinks works with independent pubs, gastropubs and hotel groups across the region, and trade customers can register for a trade account to order online.
The 80/20 rule will not fix a bar on its own, but it will tell you where to look first. Get your top lines right, keep them in stock, and stop funding the ones that sit.
Swallow Drinks has supplied the on-trade for over 40 years as a family-run independent wholesaler, with a broad portfolio of premium wine, beer, spirits and soft drinks, consistent six-day-a-week delivery, and a team that knows the local trade. Register for a trade account and let us help you build a stock list that earns its shelf space.
Roughly 80% of your sales come from about 20% of your stock lines. In practice, a small group of spirits, beers and wines does most of the work behind your bar. The other 80% of lines sell slowly and tie up cash. The 80/20 rule, also called the Pareto principle, helps you see which lines deserve the most attention and which ones are quietly draining your margin.
List every stock keeping unit, note its sales over a set period such as four weeks, and calculate its share of total revenue. Rank lines from highest to lowest revenue and add the percentages cumulatively. The point where you reach about 80% of revenue shows your top tier. Those lines are your priority for stock levels, ordering frequency and shelf position.
It works best as a starting point rather than a fixed law. Small bars often find the split is closer to 70/30 or 90/10 depending on their menu. The value is in the habit: reviewing which lines earn their space and which do not. Combine it with ABC analysis and regular stock counts so seasonal shifts, such as a busy December, do not leave you overstocked in January.
Slow-moving lines are where waste hides. They sit past their best, get poured away or quietly expire. By focusing attention on the lines that actually sell, you order more accurately, reduce dead stock and free up cash for the products your customers ask for. A supplier that understands your menu, like Swallow Drinks, can help you adjust orders as demand shifts.
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