Profit margin vs markup: why the same percentage gives different prices

The denominator is the difference

Markup compares gross profit with cost. Gross margin compares gross profit with selling price. Because the denominators differ, a 25% markup is not a 25% margin.

These are arithmetic relationships, not recommendations about the right price for your business. Use comparable costs and prices in one currency. Gross profit in this example excludes overhead, interest and tax; it is not money available to withdraw.

A $75 cost and a $100 selling price

Gross profit is $100 − $75 = $25. Gross margin is $25 ÷ $100 × 100 = 25%. Markup is $25 ÷ $75 × 100, approximately 33.33%. Enter a cost of 75 and a selling price of 100 in the Profit-margin Calculator to check the result.

Now start from a $75 cost and apply 25% markup. The price is $75 × 1.25 = $93.75. Gross profit is $18.75, and the margin is $18.75 ÷ $93.75 × 100 = 20%. The smaller result is not an error: you changed what the percentage measures.

A discount comes out of the gross profit

If the original $100 price is discounted by 10%, the customer pays $90. With the same $75 cost, gross profit becomes $15. Margin is now $15 ÷ $90 × 100, approximately 16.67%. Gross profit fell by $10, which is 40% of the original $25 gross profit.

A discount can still be a deliberate choice, but calculate the effect before agreeing it. The free Discount Calculator applies one percentage discount; it does not model stacked promotions, changing taxes or card processing fees.

• Calculate the price after discount.
• Keep the cost basis consistent.
• Recalculate gross profit and margin using the new price.
• Check overhead and capacity separately before accepting work.

Check costs before copying a percentage

For a project, include the cost items relevant to the job: materials, labour, supplier charges and travel where applicable. A missing cost can make a high displayed margin misleading. Use the Project-cost Estimator as a planning aid, then compare the estimate with actual costs.

Zero or negative denominators require care. Margin on a zero selling price is undefined, and markup on zero cost is not a meaningful finite percentage. Do not replace these conditions with an attractive-looking zero.