Two painters bid the same job. Same scope, same paint, same crew. Both of them say they price at 50%.
One quotes $1,500. The other quotes $2,000.
Neither one is lying. They are using the same word for two different pieces of math, and it costs the first painter $500 on one job.
Do that eighty times a year and it is $40,000.
The two numbers are not the same number
Markup is what you add on top of your cost. It is measured against your cost.
Margin is what you keep out of the price. It is measured against the price.
Same job, same dollars, two different denominators. That is the entire problem.
Take a job that costs you $1,000 to produce. Labor, materials, sundries, cleanup, all of it.
Marking it up 50%:
$1,000 × 1.5 = $1,500
Profit is $500. But $500 out of a $1,500 price is a **33.3% margin**, not 50%.
Pricing at a 50% margin:
$1,000 ÷ 0.50 = $2,000
Profit is $1,000. That is half the price, which is what 50% margin means.
The painter who marks up 50% thinks he is making half. He is making a third.
Why this is so easy to get wrong
obody teaches this. You learn to bid from the guy who trained you, and he learned it from the guy who trained him, and somewhere back down that line “add 50%” became the rule of thumb.
It also sounds right. Fifty percent is fifty percent. The word “percent” hides which number you are taking a percentage of, and cost and price are not the same number.
The gap widens as the percentage climbs. At small numbers the two are close enough that the error stays invisible.
| You mark up | Your actual margin is |
|---|---|
| 10% | 9.1% |
| 20% | 16.7% |
| 25% | 20.0% |
| 33% | 24.8% |
| 40% | 28.6% |
| 50% | 33.3% |
| 67% | 40.1% |
| 75% | 42.9% |
| 100% | 50.0% |
| 150% | 60.0% |
At a 10% markup you are off by less than a point and it does not matter much. At a 50% markup you are off by almost 17 points, and on a $30,000 exterior that is real money walking out the door.
The table that fixes it
Stop converting. Start with the margin you want and divide.
Price = cost ÷ (1 − margin)
| Margin you want | Divide your cost by | Which is the same as a markup of |
|---|---|---|
| 20% | 0.80 | 25% |
| 25% | 0.75 | 33% |
| 30% | 0.70 | 43% |
| 35% | 0.65 | 54% |
| 40% | 0.60 | 67% |
| 45% | 0.55 | 82% |
| 50% | 0.50 | 100% |
| 55% | 0.45 | 122% |
Want 40% on that $1,000 job? $1,000 ÷ 0.60 = $1,667.
Want 50%? $1,000 ÷ 0.50 = $2,000.
That is it. One division, and the number you set is the number you keep.
Why dividing is better than adding
It is not just that dividing gets the right answer. It changes what you are doing when you price a job.
When you add a markup, the price is an output. You total your costs, tack on a percentage, and whatever comes out is the number.
When you divide by your margin, the margin is the input. You decide what you need to keep before you look at the price, and the price arranges itself around that decision.
That sounds like a small distinction. It is the difference between finding out what you made after the job and deciding it before you bid.
The part that makes it worse: discounts
Here is where the markup painter gets hit twice.
A homeowner asks for 10% off. Feels small. Costs more than it looks.
At a 50% margin:
Full price $2,000, cost $1,000, profit $1,000.
After 10% off: price $1,800, profit $800.
You gave up 10% of the price and 20% of your profit.
At a 33.3% margin, the markup painter:
Full price $1,500, cost $1,000, profit $500.
After 10% off: price $1,350, profit $350.
Same 10% discount. He gave up 30% of his profit.
The thinner your margin, the more every point of discount costs you. The painter who confused markup with margin is not just making less on every job. He is also losing more every time he sharpens a pencil.
Your realized margin after a discount:
Adjusted margin = (margin − discount) ÷ (1 − discount)
A 50% margin with 10% off lands at 44.4%. Worth knowing before you agree to it, not after.
What to do Monday
Find out where you actually are. Take your last three finished jobs. Total what you sold them for. Total what they actually cost you, labor and materials both. Subtract, divide by the sale price. That is your real margin, and it is probably not the number you have been telling yourself.
Pick a margin, not a markup. Decide what the business needs to keep. Overhead, a truck payment, a slow February, and something left over. That is your target.
Divide, do not add. Cost divided by one minus your margin. Write it on the inside of your bid folder if you have to.
Know your cost basis. None of this works if your cost number is a guess. That means real production rates for the work you do, your actual labor rate loaded with taxes and insurance, and materials priced at what you pay, not what the shelf says.
If you want to see what happens to a trade that prices without one, a hundred painters quoted the same bedroom and the answers ran from $200 to $2,350.
The math here is not hard. It is one division. What makes it hard is that most painters have never had a reliable cost number to divide, so they reach for a markup instead and hope.
Fix the cost basis and the margin question answers itself.