Every store has that one number no one questions anymore: a 30% markup on cost, across the board. Fast-moving items, niche products, items carried only to round out the assortment, and those that compete directly with the store next door—all follow the same formula, with the same margin. It seems prudent: one standard, applied without exception, that is hard to challenge in a meeting.
But that number, which looks like discipline, is usually the opposite. Applying the same margin to every product is not a pricing policy—it is the absence of one. It is the clearest sign that the decision stopped at cost and never reached the market.
The mistake isn’t using a cost-plus-margin calculation. It’s applying the same margin every time, to every product and every customer, as if the market didn’t matter.
The formula isn't the problem—the fixed margin is
Cost-plus pricing is by far the most common way to set a price. This is not a management failure: it is how most companies, large and small, operate day to day. The problem is not starting with cost. It is stopping there.
A company can use this formula in two very different ways, even if the calculation looks identical on paper. In the first, the margin is arbitrary: a number used only to cover expenses and leave some profit, with no connection to competitors’ prices or how much customers value the product. In the second, the margin varies—and that variation brings in the market insight the formula alone lacks.
Put another way, the formula is just the structure. What actually determines the price—cost, competition, or perceived value—is the substance. Both can coexist in the same spreadsheet, which can mislead anyone who looks only at the calculation and concludes that “this company uses cost-based pricing.” It may simply be using cost-plus pricing as a calculation method, with the margin accounting for every factor beyond cost.
What a Single Margin Really Reveals
When the margin is the same for every item in the catalog, it is not tied to anything. It does not account for one product competing against three lower-priced alternatives while another has no direct substitute in the region. It does not account for one customer buying in bulk and negotiating terms while another pays upfront without question. Nor does it account for the difference between an entry-level product designed to attract customers and a long-tail product that maintains its margin because few competitors carry it.
A margin that varies by product, customer, and channel is the opposite: it shows that pricing is incorporating information beyond cost. It is not a mess—it is the margin doing what it should: connecting what the company spends with what the market is willing to pay.
This applies both to businesses that need to match a competitor’s price and to those that can charge for what sets their offering apart. In the first case, the margin is used to check whether the result aligns with the prevailing market price. If it does not, the final price is adjusted accordingly, and the original margin becomes merely a starting point. In the second, the margin brings the price closer to the value customers perceive—so it tends to be higher precisely where differentiation is greater, not where costs are higher.
Why So Many Companies Still Use a Single Margin
If a fixed margin is a symptom, why is it so common? Three reasons come up again and again.
- It's easier to calculate. A single rule applied to the entire price list saves time—until a product starts breaking even or inventory begins piling up, and no one knows why.
- It’s easier to justify internally. “We apply 35% across the board” sounds like a technical criterion. Explaining why product A gets 20% and product B gets 50% requires a rationale, and not every company is in the habit of documenting it.
- The right tools to calculate differently are lacking. Varying margins by product and customer without losing sight of overall results requires tracking the volume, turnover, and break-even point of each product line at the same time—a task that becomes difficult to manage in a manual spreadsheet once there are more than a few dozen items.
This third point was directly tested in a 2023 FIPECAFI master’s study conducted by Edson Clementino da Silva with 70 small business managers. The experiment divided participants into three groups, each with more information than the previous one: market price only; price plus cost structure; and, finally, costs along with a spreadsheet for calculations and simulations. The technically correct price was R$ 263.29. Only the third group, which had a calculation tool, came close—with an average of R$ 266.22 and a standard deviation of R$ 3.93. Seeing the cost alone did not improve pricing accuracy; having a simulation tool did.
The takeaway for using a single margin is straightforward: companies do not stick to one margin for lack of trying. Setting margins individually without losing sight of the overall picture requires a method—and here, that means having some way to calculate and model the results before settling on a figure.
The calculation changes depending on the margin used
It’s worth emphasizing a distinction that often gets lost in the discussion: markup and margin are not the same thing, even though both are often described as a “percentage added to the price.”
Cost-based markup adds a percentage to the cost:
price = cost × (1 + markup)
Price margin starts with the final price and calculates how much remains after costs:
price = cost ÷ (1 − margin)
The difference becomes clear with an example. A product that costs R$ 50.00:
- With a 35% markup on cost: 50 × 1.35 = R$ 67.50
- With a 35% margin on the selling price: 50 ÷ 0.65 = R$ 76.92
Applying the same calculation to a second product that costs R$ 50.00, but using a 60% markup because it faces less competition: 50 × 1.60 = R$ 80.00. Two products with the same cost, two different prices—R$ 67.50 and R$ 80.00—because the margin reflects different information about each one. This R$ 12.50 difference between the two prices could never result from using a single margin; here, it comes from a pricing decision, not from cost. Checking both scenarios with a markup calculator helps avoid mixing up the two calculations when adjusting an entire price list.
A Margin by Choice, Not by Habit
The practical starting point is easy to state but hard to maintain: every margin in the catalog should have a rationale that someone can explain in one sentence. “This item has a higher margin because it has no direct competitor.” “This one has a lower margin because it draws customers into the store.” When the answer is “because that’s the margin we’ve always used,” the formula is running on autopilot, with no one actively making the decision.
That does not mean abandoning cost as a starting point—it remains the floor below which no price is sustainable. It means no longer treating margin as a constant and instead treating it as the variable it should always have been: where competition and value enter the equation, product by product. The complete framework for restructuring this decision, including the criteria behind each step, is available in how to price retail products.
