Home Addition Cost Calculator

Square Feet:

Cost per Sq Ft ($):

How the Home Addition Cost Calculator works

Formula. Estimated cost = square feet × cost per square foot. The low end is that cost × 0.7 and the high end is that cost × 1.3.

Example. 200 square feet at $150 per square foot is 200 × 150 = $30,000. The displayed range is 30,000 × 0.7 = $21,000 to 30,000 × 1.3 = $39,000.

Limitation. The 0.7 and 1.3 multipliers are fixed. The page does not price permits, finishes, or local labor.