Square Foot Estimate Calculator

Frequently Asked Questions

How much does it cost to build per square foot in the US?

The national average construction cost is $150 to $250 per square foot for a standard new home build in 2026. This varies significantly by region — coastal cities like San Francisco and New York run $300 to $500+ per square foot, while the Southeast and Midwest average $120 to $200 per square foot.

What is included in a cost per square foot estimate?

A square foot estimate typically includes materials, labor, permits, and standard finishes. It does not include land cost, demolition of existing structures, major utility connections, landscaping, furniture, or high-end custom finishes. Site conditions like poor soil, steep grades, or limited access can add 10-30% to the base estimate.

Why do construction costs vary so much by location?

Labor rates, material transport costs, local permit fees, energy code requirements, and cost of living all vary by region. A framer in Sacramento earns less than one in San Francisco. Lumber delivered to a rural site costs more than lumber delivered to a metro area. Building codes in California require more insulation and energy efficiency measures than codes in Texas. These factors compound across every trade.

How much does it cost to build an ADU per square foot?

ADU construction costs range from $150 to $400 per square foot in most US markets. California averages $200 to $350 per square foot. Garage conversions are the most affordable ADU type ($150 to $250/sq ft) because the shell already exists. Detached new-build ADUs run $250 to $400/sq ft in high-cost markets.

Is it cheaper to renovate or build new per square foot?

Renovation typically costs $80 to $200 per square foot — less than new construction ($150 to $300+). But renovations are harder to estimate because you discover problems (rot, outdated wiring, plumbing issues) after demolition starts. New construction has more predictable costs because you’re building from a known starting point.

How accurate are square foot estimates?

Square foot estimates are planning-level numbers — typically accurate within 15-25% of final cost. They’re useful for budgeting and comparing options but should not replace a detailed bid from a licensed contractor who has visited your site and reviewed your plans. Actual costs depend on site conditions, design choices, material selections, and local market conditions that a calculator cannot capture.

What is the most expensive part of construction per square foot?

Labor is the largest cost component in most construction projects — typically 40-50% of total cost. Materials account for 30-35%, and permits, engineering, and overhead make up the remaining 15-25%. In high-cost markets like California and New York, labor’s share increases because wage rates are significantly above the national average.

How much does a garage conversion cost per square foot?

Garage conversions cost $150 to $300 per square foot in most markets. The lower end reflects basic conversions — insulation, drywall, flooring, basic electrical and plumbing. The higher end includes a full kitchen, bathroom, and premium finishes. The existing structure (walls, roof, foundation) reduces cost compared to a ground-up build.

How do permit costs factor into square foot estimates?

Permit fees typically add $5 to $30 per square foot depending on your jurisdiction. A $5,000 permit on a 1,000 sq ft project adds $5/sq ft. A $15,000 permit on the same project adds $15/sq ft. California cities tend toward the higher end. Some cities waive impact fees for smaller structures like ADUs under 750 square feet.

How much does commercial construction cost per square foot?

Commercial build-outs range from $100 to $500+ per square foot depending on the use. A basic retail shell runs $100 to $200/sq ft. Office build-outs with HVAC, data wiring, and partition walls run $150 to $300/sq ft. Medical and laboratory spaces run $300 to $500+ due to specialized mechanical, plumbing, and regulatory requirements.