Free construction cost estimator
This free construction cost estimator adds your line items (material, labor hours times rate, equipment and subcontractor quotes), then applies material waste, sales tax, contingency, overhead and profit to give a bid price. Profit can be entered as a markup on cost (price = cost × (1 + markup)) or a margin on price (price = cost ÷ (1 − margin)), and the result always shows both, because a 10% markup is only a 9.1% margin. It runs in your browser and exports a CSV.
That profit is a 10.0% markup on cost and a 9.1% margin on price.
| Item | Basis | Amount |
|---|---|---|
| Material | Sum of material lines | $10,000.00 |
| Waste | 5% of material | $500.00 |
| Sales tax | 0% of material plus waste | $0.00 |
| Labor | Hours × rate | $9,600.00 |
| Equipment | Sum of equipment lines | $1,500.00 |
| Subcontractors | Sum of quotes | $4,000.00 |
| Direct cost | $25,600.00 | |
| Contingency | 0% of direct cost | $0.00 |
| Overhead | 10% of direct cost plus contingency | $2,560.00 |
| Total cost | $28,160.00 | |
| Profit | 10% markup: cost × 1.1000 | $2,816.00 |
| Bond | 0% of price before bond | $0.00 |
| Bid price | $30,976.00 |
How to use the construction estimate calculator
- Enter the direct costs as lines. Pick a type for each line. Material lines take a quantity and unit cost, labor lines take hours and an hourly rate, equipment lines take days or units and a rate, and subcontractor lines take the quote. Replace the four example lines with your own.
- Set the waste. The waste percentage applies to material only: offcuts, breakage, and the small parts that never make it onto a takeoff. Use the figure your own jobs support.
- Set sales tax. Tax applies to material plus waste. Whether labor, equipment or the whole contract is taxable depends on the state and the contract type, so check before you change the default of 0%.
- Add contingency and overhead. Contingency is a percentage of the direct cost held for the unknowns in the drawings. Overhead covers the office, insurance, vehicles and the estimator's time; it's applied to direct cost plus contingency.
- Choose markup or margin. Enter profit the way your company talks about it. The verdict line converts it to the other one.
- Add the bond, if any. Bond is entered as a percentage of the price. The real premium comes from your surety, so treat this as a placeholder until you have their quote.
- Export. "Download as CSV" writes every line plus the summary, so the estimate opens in Excel or Google Sheets.
The formulas behind the estimate
Direct cost = material + (material × waste %) + tax on material and waste + labor hours × rate + equipment + subcontractors
Total cost = direct cost + contingency + overhead
Price with markup = total cost × (1 + markup)
Price with margin = total cost ÷ (1 − margin)
Bid price = price + bond
Some contractors apply overhead and profit in one step, or apply overhead to labor only. Neither is wrong as long as the company's overhead rate was calculated the same way. If your overhead rate came from last year's overhead divided by last year's direct cost, apply it to direct cost, as this calculator does.
Markup vs margin: what's the difference?
Markup is profit as a percentage of cost. Margin is profit as a percentage of the selling price. The same dollars of profit give a smaller margin than markup, because the price is a bigger number than the cost. Converting between them:
margin = markup ÷ (1 + markup) | markup = margin ÷ (1 − margin)
| Markup | Margin | Price on $100,000 of cost |
|---|---|---|
| 10% | 9.09% | $110,000.00 |
| 15% | 13.04% | $115,000.00 |
| 20% | 16.67% | $120,000.00 |
| 25% | 20.00% | $125,000.00 |
| 30% | 23.08% | $130,000.00 |
| 50% | 33.33% | $150,000.00 |
Worked example
An illustrative small job, not from a real project, with 5% waste, 6% sales tax on material, no contingency and 10% overhead:
| Line | Basis | Amount |
|---|---|---|
| Material | From the takeoff | $10,000.00 |
| Waste | 5% of material | $500.00 |
| Sales tax | 6% of $10,500.00 | $630.00 |
| Labor | 160 h × $60/h | $9,600.00 |
| Equipment | Lift, 5 days × $300 | $1,500.00 |
| Subcontractor | Quote | $4,000.00 |
| Direct cost | $26,230.00 | |
| Overhead | 10% of direct cost | $2,623.00 |
| Total cost | $28,853.00 | |
| Price, 10% markup | $28,853.00 × 1.10 | $31,738.30 |
| Price, 10% margin | $28,853.00 ÷ 0.90 | $32,058.89 |
The gap between the last two lines, $320.59, is the whole markup vs margin difference on one small job. On a year of bids it adds up to real money in one direction or the other.
Common mistakes in a construction cost estimate
Confusing markup and margin
The owner says "we run 20%" meaning margin, the estimator adds a 20% markup, and the job is priced at a 16.7% margin. Agree on which one the company means and label it in the estimate.
Subtracting a margin to check a price
Taking 10% off a price doesn't give you the cost behind a 10% markup. $110 minus 10% is $99, not $100. Use the formulas above in both directions.
Waste on everything
Waste belongs on material. Applying it to labor or to a subcontractor's lump sum inflates the price without a reason you can explain.
Labor without burden
A labor rate that's only the wage leaves out payroll taxes, insurance and benefits. Use a burdened rate, or carry the burden in overhead, but not neither.
Overhead as a guess
Your overhead rate should come from your books: annual overhead divided by the base you apply it to. A borrowed industry number can be far from your real cost.
Quantities nobody checked
Every percentage multiplies the quantities. A miscount in the takeoff carries straight through waste, tax, overhead and profit.
When to move from a calculator to a spreadsheet or software
A calculator like this is right for a quick price, a change order or a check on someone else's number. For a full bid with dozens of cost codes, a spreadsheet gives you more room: start from the construction estimate template, and the guide to construction estimating with Excel covers formulas, lookups and where spreadsheets break. Past that point, the construction estimating software guide compares the tools, including free options.
The price is half of a bid. The other half is getting it to the right GC on time and seeing how it levels against the other subs, which is what the guide to construction bidding software is about, including the bid management side GCs use to compare your number.
Electrical contractors have a dedicated version of this page: the electrical estimate calculator works per device and fixture with labor hours per unit, and the electrical cost per square foot guide gives a way to check its result against past jobs of the same building type. AmpCount, which makes this page, counts electrical devices and fixtures from the plans; it doesn't price the job.