Tested tool guide
Tested browser tools
Checked August 16, 2026
What Markup Calculator does, with a checked example
Translate between unit cost, selling price, markup on cost, and margin on sales. In the forward direction, enter cost and markup percentage to obtain the selling price and compare that markup with the resulting gross margin. In the reverse direction, enter cost and selling price to determine the markup that was applied. The common trap is treating markup and margin as interchangeable percentages: markup divides profit by cost, while margin divides the same profit by selling price, so their percentages differ whenever profit is nonzero.
Worked example
A concrete input and expected output from the current implementation.
Input
Cost: $80; markup: 25%
->
Expected output
Selling price: $100; markup: 25%; margin: 20%.
A 25% markup adds 0.25 x $80 = $20 to cost, producing $100. The margin uses selling price as its denominator, so it is $20 / $100 = 20%, not 25%.