The single most expensive math mistake in contracting is confusing markup with margin. A contractor who thinks they are making a 25% profit margin when they are actually applying a 25% markup is earning only 20% margin. On $500,000 in annual revenue, that five-percentage-point gap represents $25,000 in profit they think they have but do not. This interactive converter eliminates the confusion permanently. Slide the markup percentage and watch the margin update in real time, or enter a target margin and see the markup you need to apply. A reference table shows the most common equivalences, and a concrete dollar example makes the math tangible. Bookmark this page. Every contractor who has ever set a 20% markup thinking it was a 20% margin needs this tool.
| Markup | Margin | On $1,000 cost |
|---|---|---|
| 10% | 9.1% | $1,100 |
| 15% | 13.0% | $1,150 |
| 20% | 16.7% | $1,200 |
| 25% | 20.0% | $1,250 |
| 30% | 23.1% | $1,300 |
| 33.3% | 25.0% | $1,333 |
| 50% | 33.3% | $1,500 |
| 100% | 50.0% | $2,000 |
Markup and margin both measure profit, but from different starting points. Markup is calculated as profit divided by cost: if your cost is $800 and you sell for $1,000, your profit is $200, and your markup is $200 / $800 = 25%. Margin is calculated as profit divided by selling price: the same $200 profit on a $1,000 sale gives a margin of $200 / $1,000 = 20%.
The converter uses these formulas bidirectionally. Enter a markup percentage and it calculates the equivalent margin. Enter a target margin and it shows the markup you need to apply. The slider provides an intuitive visual way to explore the relationship. The reference table below shows the most common pairs that every contractor should memorize: 25% markup equals 20% margin, 50% markup equals 33.3% margin, and 100% markup equals 50% margin.
Use this converter when discussing pricing with a partner or accountant to make sure you are speaking the same language. Use it when a supplier quotes you a price with a suggested markup: check what margin that actually delivers. Use it when reading industry benchmarks: some sources report in markup, others in margin, and mixing them up leads to bad decisions. And use it when training a new estimator who has not yet internalized the difference. The interactive slider makes the concept click faster than any explanation.