Profit Margin Calculator
Calculate gross profit and margin percentage from cost and selling price.
How to use the Profit Margin Calculator
Enter your values and pick a mode if the tool offers one.
Click calculate — results appear instantly, computed in your browser.
Copy the result or save the tool to your favorites.
Frequently asked questions
Profit as a percentage of the selling price: (price − cost) / price × 100.
Margin is profit over selling price; markup is profit over cost. Markup is always the larger percentage.
Yes, if you sell below cost — the result shows a loss as a negative percentage.
No. Use figures excluding GST, or apply GST separately.
Entirely in your browser.
About the Profit Margin Calculator
This calculator turns a cost price and a selling price into the three numbers every business owner needs: profit, profit margin, and markup. Though margin and markup are often confused, they answer different questions, and understanding both is essential for pricing correctly.
Margin versus markup
Profit is simply selling price minus cost. Margin expresses that profit as a percentage of the selling price, while markup expresses it as a percentage of the cost. Because the selling price is always larger than the cost, margin is always a smaller percentage than markup for the same transaction. For example, buying at 80 and selling at 100 gives a profit of 20: that is a 20% margin (20 out of 100) but a 25% markup (20 out of 80). Confusing the two is a common pricing mistake that quietly erodes profitability.
Why the distinction matters
If you want every sale to keep a certain share of revenue as profit, you are thinking in margin. If you set prices by adding a fixed percentage to what you paid, you are thinking in markup. A retailer who applies a 25% markup is not making a 25% margin; they are making a 20% margin. Setting prices with the wrong one leads to thinner profits than expected, especially at scale.
How to use it
Enter your cost price and the price you sell at. The calculator returns the absolute profit, the margin percentage, and the markup percentage at once, so you can see all three perspectives on the same transaction. If the selling price is below cost, the profit and percentages turn negative, showing the size of the loss.
Practical applications
Use it to check whether a product is priced healthily, to compare the profitability of different items, and to decide how much room you have for discounts before a sale stops being worthwhile. It is equally useful for freelancers pricing services, where the cost is your time and overhead, and for retailers managing many SKUs with different margins.
Tips
Work with figures that exclude tax, then add GST separately so tax does not distort your margin. Remember that a discount cuts into margin faster than it might appear, because the saving comes entirely out of profit. To model discounts use the Discount Calculator, to handle tax use the GST Calculator, and to measure investment returns rather than trading margins, the ROI Calculator. Everything is computed in your browser and nothing is stored.