The denominator changes the answer
For a product with cost C and selling price P, the dollar difference is P − C. Markup and margin express that same difference relative to different bases.
Markup = (price − cost) ÷ cost × 100%
Margin = (price − cost) ÷ price × 100%
A product that costs $60 and sells for $90 has $30 of gross profit before expenses not included in cost. The markup is $30 ÷ $60 = 50%. The margin is $30 ÷ $90 = 33.33%.
Neither formula is more correct. The error is using one name while calculating the other.
Set a price from a target margin
To achieve a target margin, divide cost by one minus the target margin expressed as a decimal.
Price for target margin = cost ÷ (1 − target margin)
At a $60 cost and a 40% target margin, the required price is $60 ÷ 0.60 = $100. Multiplying $60 by 1.40 gives $84, which is a 40% markup but only a 28.57% margin.
| Cost | Selling price | Markup | Margin |
|---|---|---|---|
| $60 | $75 | 25% | 20% |
| $60 | $90 | 50% | 33.33% |
| $60 | $100 | 66.67% | 40% |
| $60 | $120 | 100% | 50% |
A 100% target margin is not attainable at a finite positive selling price when cost is positive. A 100% markup, however, simply means doubling cost.
Convert directly between the percentages
Using decimal inputs, margin = markup ÷ (1 + markup), and markup = margin ÷ (1 − margin). Multiply the result by 100 to display a percentage.
These conversion formulas assume the same cost and price basis. They do not reconcile different accounting definitions. One department might include shipping in cost while another does not; converting their percentages will not fix that inconsistency.
Keep calculation precision until the final displayed price. If you round a calculated price down, check the resulting margin again. A rounded retail price can fall slightly below the intended target.
Decide what belongs in cost
For a simple merchandise example, cost may include the purchase price plus freight into inventory. For a service, direct labor or subcontracting may be relevant. Payment processing, outbound shipping, refunds, and commissions can also affect contribution even when they are not classified in the same accounting line.
Label the result accordingly. Gross margin, contribution margin, and net profit margin are not interchangeable. A product's gross margin can look healthy while corporate overhead, rent, and acquisition costs leave the business unprofitable.
For pricing decisions, build a contribution view that includes expenses that change with the sale. Reconcile it separately with the accounting statements rather than assuming a single percentage captures every cost.
Discounts reduce margin faster than revenue
Take the $100 selling price and $60 cost from the example. A 10% discount lowers price to $90. Dollar contribution falls from $40 to $30, a 25% reduction, while margin falls from 40% to 33.33%.
That is why “only 10% off” can have a much larger effect on profit. Calculate the extra volume required to replace the lost contribution, including any new fulfillment or campaign costs.
Handle unusual values honestly
At zero cost, markup is undefined because its denominator is zero; margin may still be defined if price is positive. At zero selling price, margin is undefined. A loss-making sale produces a negative margin and negative markup when both original denominators are positive.
Do not replace undefined values with zero. Show the dollar result and explain the denominator problem. That makes a pricing calculator more useful than a visually tidy but incorrect percentage.
Frequently asked questions
What margin does a 50% markup produce?
A 50% markup produces a 33.33% margin when cost and price use the same basis.
How do I price for a 40% margin?
Divide cost by 0.60. For example, a $60 cost requires a $100 selling price before costs excluded from the model.
Can markup be calculated when cost is zero?
No. The markup denominator is zero, so the percentage is undefined. Display the dollar profit and any other meaningful metric instead.
Sources & calculation notes
The formulas and worked examples above show the calculation method. All example inputs are illustrative; a mathematical result does not validate the assumptions or replace a project-specific assessment.
Use this guide thoughtfully. Examples illustrate a calculation method, not a guaranteed outcome. The usefulness of any result depends on the definitions, measurements, and assumptions used.