A construction markup percentage is useful only when its cost base is clear. A percentage added to materials alone, an estimate that includes job overhead, and a fully allocated company cost base describe different calculations. This guide explains the arithmetic and shows how to keep those bases consistent. It supplies no recommended trade markup, wage rate or profit target.
Define cost, price and the amount between them
Let C be the estimated cost base you have explicitly defined and P the proposed selling price for the same scope. The amount above that base is P − C. Markup divides this amount by C; margin divides it by P. Rates in the formulas below are decimals: 20% is 0.20. The examples use positive costs and prices, nonnegative markups, and margin rates below 100%.
Business Victoria explains the cost denominator for markup and the sales denominator for margin. Its guidance also separates gross measures from measures after overhead. The algebra here applies to an explicitly defined estimating base; it does not supply construction-industry benchmarks.
| Calculation | Formula | Denominator or condition |
|---|---|---|
| Markup rate m | (P − C) ÷ C | Cost C |
| Margin rate p | (P − C) ÷ P | Selling price P |
| Convert markup to margin | p = m ÷ (1 + m) | Use decimal rates |
| Convert margin to markup | m = p ÷ (1 − p) | Use decimal rates |
| Price from markup | P = C × (1 + m) | Same defined cost base |
| Price from margin | P = C ÷ (1 − p) | Same defined cost base |
For example, a 20% markup converts to 0.20 ÷ 1.20 = 0.166667, or approximately 16.67% margin. A hypothetical 20% margin converts to 0.20 ÷ 0.80 = 0.25, or 25% markup. The percentages differ because their denominators differ, even though they describe the same amount above cost.
Worked example: $1.6 million cost, two different percentages
These are invented teaching inputs, not a recommended bid. Assume the same estimated cost base of $1,600,000 in both cases. It includes the defined project costs for this comparison and excludes company overhead. There are no separate taxes, financing charges or other deductions in this simplified calculation. Amounts above C are therefore not presented as final net profit.
| Measure | 20% markup on cost | 20% margin on price |
|---|---|---|
| Defined estimated cost C | $1,600,000 | $1,600,000 |
| Price calculation | $1,600,000 × 1.20 | $1,600,000 ÷ 0.80 |
| Proposed price P | $1,920,000 | $2,000,000 |
| Amount above C | $320,000 | $400,000 |
| Markup on C | 20% | 25% |
| Margin above C as a share of P | 16.67%, rounded | 20% |
The difference between these proposed prices is $2,000,000 − $1,920,000 = $80,000. Because C is identical, the amounts above C also differ by $80,000. This compares two pricing calculations; it does not prove either price will be accepted or that the estimated costs will be achieved.
Overhead: subtract percentages only when their bases match
Gross margin is the amount after cost of sales expressed as a share of revenue. If C represents cost of sales and excludes company overhead, (P − C) ÷ P can describe gross margin for that simplified scope. If C already includes company overhead, label the result as margin above that defined cost base instead. Do not subtract an expense a second time merely because it is also called overhead elsewhere.
Consider a separate hypothetical example: $100 of cost of sales, a $120 price, and company overhead allocated at 16% of that same $120 revenue. The cost base excludes this overhead pool. Assume scope and period are compatible and no other expense is included in this example.
| Step | Calculation | Result |
|---|---|---|
| Amount above cost of sales | $120 − $100 | $20 |
| Gross margin on revenue | $20 ÷ $120 | 16.6667%, approximately |
| Separate overhead allocation | $120 × 0.16 | $19.20 |
| Residual after this overhead | $20 − $19.20 | $0.80 |
| Residual as a share of revenue | $0.80 ÷ $120 | 0.6667%, approximately |
On that shared revenue base, 16.6667% − 16% is approximately 0.6667 percentage points. The dollar calculation gives the same answer. It is not 4%. An overhead rate stated as a percentage of cost would use a different denominator and cannot be subtracted from a revenue margin without conversion.
The $0.80 is only the residual in this defined example. Do not call it your business net profit without accounting for all applicable costs and the reporting basis. If the $100 already contained the $19.20 overhead allocation, deducting that allocation again would double-count the same cost.
Set up the cost base before choosing a percentage
- Materials: record what is included in supplier prices, delivery, handling and any separately estimated waste. Add a cost separately only when it is excluded elsewhere.
- Labor: identify wages, employer labor costs and the hour basis. State whether a loaded rate already contains supervision, job overhead or company overhead.
- Subcontractors: read the quoted scope and exclusions. Identify work or coordination costs that remain with you instead of assuming the subcontract price covers them.
- Job and company overhead: document each cost pool, its allocation base and where it is recovered. Keep amounts already in other estimate lines out of any additional allocation.
If you apply different markups to cost categories, review the resulting total price against the total defined cost base. A percentage on one category does not become the overall margin. This guide does not prescribe separate material, labor, subcontractor or trade percentages.
Check the calculation before using it in a bid
- Write down the scope and every cost included in C.
- Label the chosen rate as markup on cost or margin on price, and convert percentages to decimals.
- Calculate P, then independently check both (P − C) ÷ C and (P − C) ÷ P.
- Check overhead inclusions and denominator compatibility before adding or subtracting it.
- Keep the worked assumptions with the estimate. Later, compare actual revenue and actual costs using the same categories.
A correct formula makes the pricing assumption explicit. It does not verify quantities, supplier prices, labor productivity or the customer's willingness to pay. Those inputs require their own review.
Frequently Asked Questions
What is the difference between construction markup and margin?
Markup uses cost as its denominator; margin uses selling price. For the same cost base C and price P, markup = (P − C) ÷ C and margin = (P − C) ÷ P. Define the costs included in C before comparing percentages.
Does a 20% markup produce a 20% margin?
No. A cost of $100 with a 20% markup produces a $120 price and $20 above cost. That amount is 16.67% of the price, rounded. A 20% margin on a $100 cost base requires a $125 price and a 25% markup.
How do I convert a target margin to markup?
Write the margin as a decimal p and calculate p ÷ (1 − p). For a hypothetical 20% margin, 0.20 ÷ 0.80 = 0.25, or 25% markup. This conversion does not establish which margin is appropriate for a job.
Can I subtract an overhead percentage from gross margin?
Only when both percentages use the same revenue denominator for compatible scope and periods, and that overhead is excluded from the cost-of-sales base. If the same overhead is already in the cost base, subtracting it again counts it twice.
What markup should I use for materials, labor or subcontractors?
This guide supplies no recommended trade or cost-category percentages. Identify the complete costs, exclusions and overhead recovery for the work, then calculate what a proposed price leaves above that defined base. A mathematically correct percentage does not guarantee the job will earn it.