Gross margin and markup describe the same difference using different denominators. The Profit Margin Calculator reports gross profit as an amount, gross margin relative to revenue, and markup relative to cost. Keeping those bases explicit prevents a common mistake when comparing a cost figure with a selling figure.
Enter comparable cost and revenue
Fill Total cost and Total revenue, then choose Calculate. Cost must be nonnegative and revenue must be at least 0.01. Use the same currency and scope in both fields: for example, the cost and revenue of one item, or totals for the same collection of items over the same period.
Decide which costs you are including before entering a number. The tool cannot classify expenses or determine an accounting policy. The label “gross profit” represents revenue minus the supplied cost; it does not automatically subtract overhead, interest, tax, or any expense absent from that input.
Compare the two percentages by hand
With cost 70 and revenue 100, gross profit is 100 − 70 = 30. Gross margin is 30 / 100 × 100, or 30.00%. Markup is 30 / 70 × 100, or 42.86% after rounding.
The different percentages do not conflict. Margin answers “what share of revenue is the difference?” Markup answers “what share of cost is the difference?” A 30% markup on a cost of 70 would instead add 21, giving revenue 91; it would not produce the 100 used in this example.
If cost exceeds revenue, the output can be negative. With cost 120 and revenue 100, gross profit is −20, gross margin is −20.00%, and markup is −16.67%. Negative results follow directly from the supplied values and do not identify why a loss occurred.
Handle zero and rounding carefully
At zero cost and positive revenue, markup is displayed as Undefined (zero cost) because its denominator is zero. The tool still calculates the profit and margin. Zero revenue is rejected rather than assigning a misleading margin percentage.
Displayed amounts and percentages use two decimals. Avoid inferring precision beyond that of your input records, and retain the original figures when checking a reconciliation. No price recommendation or profitability forecast is generated.
The calculation stays in the browser without access to financial accounts. Use the Percentage Calculator when inspecting a general ratio. If you are evaluating an actual reduced selling price, calculate that price with the Discount Calculator first, then use consistent cost and revenue figures here to inspect the resulting arithmetic.