A markup calculator does one piece of arithmetic: price equals cost plus a percentage of cost. It is simple enough to do in your head and it is got wrong constantly, because the number most people actually want is margin, which is a share of the price rather than of the cost. The two agree at zero and diverge immediately afterwards, and a business that sets markup while thinking in margin underprices every job it does by the same predictable gap.
The two formulas, side by side
Markup is price minus cost, over cost. Margin is price minus cost, over price. Adding a third of the cost to a job gives you a quarter of the price as profit, not a third. That single confusion is the most common pricing error in small contracting and it compounds across every quote.
Work backwards from the margin you need
Decide the margin the business needs on that kind of work, then convert it to the markup that produces it: divide the cost by one minus the margin. Doing it in that order means the number you apply on the quote is derived from the number you are actually managing.
Apply it to cost, and be honest about cost
A markup on the wrong cost is still wrong. Materials at your true buying price, labour at the burdened rate rather than the wage, and any subcontract at what you pay. Marking up an understated cost is how a busy year ends with no money in it.
Questions people ask about markup calculator
How do I convert margin to markup?
Divide the desired margin by one minus the desired margin. A quarter of the price as margin is a third added to cost; a third of the price is a half added to cost. Keep a short table of the two or three you actually use.
Should markup be the same on materials and labour?
Usually not. Materials carry purchasing, handling and warranty risk; labour carries supervision and idle time. Most firms apply different figures and are clearer for doing so, provided the quote still shows a single price.
What about tax?
Tax is applied after the price is set and is not part of the markup, though the tax treatment of materials against labour differs in many places and belongs in the quote as its own line rather than inside the rate.