Square Footage Calculator
Measure any space room by room: add a row for each area, choose its shape (rectangle, circle or triangle), and enter the dimensions in feet and inches. You get the square footage of every area plus a grand total — and the total cost if you enter a price per square foot for flooring, paint or rent.
168 sq ft
Total across 1 area
Square feet
168
Square yards
18.7
How to measure a room
Measure wall to wall along the longest walls in feet and inches, and treat every alcove, closet or bay window as its own small rectangle. The formulas the calculator uses:
rectangle = length × width
circle = π × (diameter ÷ 2)²
triangle = ½ × base × height
Worked example — an L-shaped room: split it into two rectangles. The main section measures 14 ft × 12 ft = 168 sq ft, and the leg of the L is 6 ft × 8 ft = 48 sq ft. Total: 168 + 48 = 216 square feet. In the calculator, that is simply two rectangle rows — the total updates automatically.
Inches convert as twelfths of a foot: 12 ft 6 in = 12.5 ft. The calculator handles this for you — just type feet and inches in their own boxes.
Common uses for square footage
- Flooring: total the rooms, then add 5–10% for cuts and waste (15% for diagonal or patterned layouts) and round up to whole boxes.
- Paint: wall area rather than floor area — measure each wall as a rectangle (width × height), then use the paint calculator to turn square feet into gallons.
- Rent and real estate: divide monthly rent or sale price by square footage to compare homes fairly — $2,100 for 700 sq ft is $3.00/sq ft, while $2,400 for 900 sq ft is only $2.67.
- Landscaping: square footage is the first step before volume — feed your total into the mulch calculator or cubic yard calculator to get cubic yards of material.
Related calculators
For unit conversions between square feet, square meters and acres, see the area calculator. Planning outdoor projects? The gravel calculator, soil calculator and concrete calculator convert your square footage into the material you need to order.