Total Construction Cost Calculator 2026

The contingency percentage is applied to the subtotal of all category costs first. The builder overhead or margin is then applied on top of that contingency-adjusted figure. This reflects the way most construction contracts and cost plans are structured, where the contingency sits within the project cost before margin is applied.

Cost per area divides the final estimated total construction cost by the floor area you enter. This gives you a cost per square metre or square foot figure that you can compare against published benchmarks or previous projects. It only appears in the results if you enter a floor area greater than zero.

No. This calculator covers construction and trade costs only. Land cost, stamp duty, legal fees, finance charges, and connection fees are not included unless you manually add them to the Other Costs field as a combined figure.

The accuracy depends entirely on the quality of the input figures you use. If you are using early-stage budgets or square metre rates for each category, the result is an order-of-magnitude or feasibility estimate. If you are using actual quoted prices from subcontractors, the result will be much closer to the real project cost. Always treat the output as an estimate, not a final price.

Yes. The cost categories apply to commercial, industrial, and mixed-use projects in the same way as residential builds. Commercial projects typically have a higher proportion of structural, mechanical, and compliance costs, and lower interior finishing costs as a percentage of total. You can adjust each category to reflect your specific project scope.

For residential new builds at design development stage, 10% is commonly used. For early-stage feasibility or projects with significant unknowns, 15–20% is more appropriate. For well-documented projects at tender stage, 5–7% may be sufficient. Commercial and industrial projects typically carry a slightly higher contingency than residential due to the complexity of trades and compliance requirements.

No tax is calculated automatically. If tax is applicable to your project, you can either include it within individual category costs or add an additional percentage in the builder overhead field to account for it. Tax treatment varies significantly by country, project type, and client registration status.

Contingency is an allowance for unknown scope, design development, site surprises, and coordination issues. Escalation is an allowance for market price movement between the estimate date and the actual purchase or construction date. In a 2026 construction budget, both can be important because delayed starts can expose the project to new material and labour prices.

For a full project budget, yes. Design fees, engineering fees, permit charges, inspections, authority submissions, and consultant reviews are real project costs. If you only want a builder’s construction price, keep them separate; if you want a total owner budget, include them in the calculator.

Yes. Select a commercial project type and enter the cost categories that apply. Commercial projects often need higher allowances for fire protection, HVAC, electrical load, accessibility, compliance, lifts, security systems, commissioning, and professional fees, so the input figures should be based on commercial drawings or trade quotes.

Common missing items include site establishment, scaffolding, temporary works, utility connections, testing and commissioning, design fees, permits, waste disposal, insurance, landscaping, external drainage, appliances, joinery upgrades, escalation, and builder preliminaries. Use the scope checklist on this page before finalizing your estimate.