UK Profit Margin Calculator

Profit margin and markup are two of the most commonly confused numbers in pricing, and mixing them up can lead to underpricing a product or service without realising it. This calculator works out your margin and markup from a cost price and selling price, or the selling price you need to hit a specific target margin.

How to use the profit margin calculator

Choose whether you want to work out your margin from two prices you already have, or work out the selling price needed to hit a target margin. Enter your cost price, then either your selling price, or your target margin percentage. The calculator instantly shows your profit per unit, your margin, and your markup, so you can see both figures side by side.

How the calculation works

Profit is simply selling price minus cost price. Margin divides that profit by the selling price, showing what proportion of each sale is profit. Markup divides the same profit by the cost price instead, showing how much you have added on top of what the item cost you. Because margin and markup use different bases, a 50% markup does not equal a 50% margin, a common source of pricing errors.

To find a selling price for a target margin, the calculator rearranges the margin formula: selling price equals cost price divided by 1 minus the target margin, expressed as a decimal. This guarantees that, once you sell at the resulting price, your margin works out to exactly the percentage you were aiming for.

Worked example

A product costing £40 to make or buy, sold for £65, generates a profit of £25. That is a margin of £25 ÷ £65 = 38.46%, but a markup of £25 ÷ £40 = 62.5%, the same £25 profit expressed two different ways. If instead you wanted to price that same £40 product to hit a target margin of 30%, the required selling price is £40 ÷ 0.7 = £57.14, giving a profit of £17.14 and a markup of 42.86%.

Quick markup to margin conversions

Because markup and margin are calculated on different bases, the same underlying profit produces two different-looking percentages, and the gap between them grows as the numbers get bigger. A 25% markup works out as a 20% margin, a 50% markup works out as a 33.3% margin, a 100% markup, doubling your cost price, works out as exactly a 50% margin, and a 150% markup works out as a 60% margin. Notice that markup can climb well past 100%, while margin can never reach 100% at all, since it is always measured against the larger selling price figure rather than the smaller cost price.

When to think in markup versus margin

Retailers and tradespeople often think naturally in markup, since it answers the practical question of how much to add on top of a known cost price when setting a shelf or quote price. Margin, on the other hand, is generally the more useful figure for understanding overall business profitability, since it directly shows what proportion of total revenue ends up as profit, which links more naturally to financial statements, forecasting and comparing performance year on year. Neither figure is wrong, but using the right one for the decision in front of you, and being clear with colleagues, accountants or lenders about which one you mean, avoids misunderstandings that can lead to underpriced products.

Ways to improve a thin margin

If this calculator shows a margin lower than you would like, there are generally two levers to pull: increasing the selling price, or reducing the cost price. Raising price is the most direct option, though it needs to be balanced against what customers are willing to pay and what competitors charge. On the cost side, negotiating better supplier terms, buying in larger volumes, reducing waste or returns, and reviewing packaging and delivery costs can all lower your cost price without touching the price customers see at all. Even a small reduction in cost price can meaningfully improve margin, since it drops straight through to profit rather than being partly offset by tax or other costs the way extra revenue sometimes is.

Common mistakes to avoid

The most common mistake is applying a markup percentage while assuming it will produce the same margin percentage, which systematically underprices products, since markup on cost is always a smaller number of pounds than the equivalent margin on selling price. Always be clear about which figure you are working with, especially when comparing pricing strategies with someone else, or with a spreadsheet template that may use a different convention.

Another mistake is calculating margin from prices that are not on a consistent VAT basis, mixing a VAT-inclusive cost with a VAT-exclusive selling price or vice versa, which distorts the result. It is also easy to overlook other per-unit costs beyond the direct cost price, such as payment processing fees or delivery costs, which can meaningfully erode a margin that looks healthy on paper.

Related calculators

Once you know your margin, our break-even calculator shows how many units you need to sell to cover your fixed costs at that price. Our VAT calculator can add or remove VAT before you compare prices, our discount calculator checks the effect of a sale price on your margin, and our Corporation Tax calculator estimates the tax due once profit reaches the company level. Our self-employed tax guide also covers pricing and profit considerations for sole traders.