The most dangerous job is the one that looks profitable and is not. You quote it, you win it, you finish it, and the money in the bank is somehow less than you expected. Nothing went obviously wrong. The leak was in the math the whole time.
This calculator puts a true number on any job. Adjust the figures above and watch your real margin, your real markup and your profit per hour move in real time.
Why most contractors do not know their true margin
Ask a busy contractor what their margin is and you will usually hear a markup figure instead. They add a percentage on top of materials and labor, call it the margin, and move on. The number feels right because it is the number they chose. The problem is that two different mistakes are baked into it, and both push real profit down.
The first mistake is ignoring overhead. The price gets compared against the cost of materials and the cost of labor, and whatever is left over is treated as profit. But the truck, the insurance, the software, the phone, the fuel and the unpaid hours spent quoting and chasing invoices all have to be paid out of the jobs you win. If those costs never enter the job math, every job looks healthy while the business quietly loses ground.
The second mistake is confusing markup with margin. They are not the same number and they never will be. That gap is where a lot of trade businesses lose their profit without ever seeing it on a single invoice.
Overhead allocation, in plain terms
Overhead allocation is the practice of making each job carry a fair share of your fixed costs. The simplest method is a percentage on top of direct cost. If your annual overhead is roughly a fifth of your annual direct job costs, you allocate about 20% of each job's materials-plus-labor as that job's overhead share.
The calculator does exactly this: it takes your materials and labor, applies your overhead percentage, and adds the result to get total cost. Net profit is the price minus that total cost, not minus materials and labor alone. The difference is often the difference between a job that funds the business and one that drains it.
Start with a realistic percentage. If you have never measured it, 12% to 15% is a reasonable opening estimate, and you should refine it as soon as you have real annual numbers. A directional model with honest inputs beats a precise model with a fantasy overhead of zero.
Margin versus markup, settled with numbers
Here is the distinction that costs contractors the most money.
- Markup is profit as a share of your cost. A $10,000 cost sold for $13,000 carries a 30% markup, because the $3,000 of profit is 30% of the $10,000 cost.
- Margin is profit as a share of your price. That same $3,000 of profit on a $13,000 price is a 23% margin, because $3,000 is 23% of $13,000.
Same job, same dollars, two different percentages. Markup is always the larger one. So when you set a 30% markup and tell yourself you are running a 30% margin, you are overstating your real profitability by roughly seven points on every job. Over a year of quotes, that adds up to serious money left on the table.
The fix is not complicated: decide in margin terms, then convert to a price. For a target margin, the price is your cost divided by one minus the margin as a fraction. The markup and margin calculator does that conversion for you, and this tool shows both numbers on every result so the gap stays visible.
What to do with the result
If the true margin came in lower than you expected, that is the tool doing its job. You have two levers: raise the price or cut the cost. Raising the price is usually the better lever, because a small price increase flows almost entirely to profit, while cost-cutting often means cutting corners that come back as callbacks.
Before you accept a job under 15% margin, sanity-check your inputs. Are the hours realistic? Is the overhead percentage honest? Did you include your own labor at a real rate? If you have not yet set a defensible hourly rate, run the contractor hourly rate calculator first, because labor priced too cheaply hides the leak.
For the bigger picture on running a profitable trade business, the operations page covers how pricing, overhead and capacity fit together, and the science of pricing guide goes deeper on setting numbers that hold up. When you want to pressure-test your pricing against your real books, talk to us.