Square footage calculator
Add rooms or sections one at a time. Split odd shapes into rectangles, triangles and circles.
Quick answer: square footage = length × width in feet. A 12 × 15 ft room is 180 sq ft (16.7 m² or 20 sq yd). For an L-shaped room, split it into two rectangles and add them. Buy about 10% extra flooring for cuts and waste.
Area calculator
Tip: enter 12 ft 6 in as 12.5.
0 sq ft
How this is calculated
- Rectangle or square: length × width.
- Triangle: base × height ÷ 2 (for a corner cut-off or a bay).
- Circle: π × (diameter ÷ 2)² (for round rooms or rugs).
- Conversions: 1 sq ft = 0.092903 m²; 9 sq ft = 1 sq yd.
- Flooring to buy = total × (1 + waste %). Cost = flooring to buy × price per sq ft.
The square footage on a home listing is usually the finished, heated living area measured from the outside of the walls, so adding up rooms from the inside will give a smaller number. That difference is normal.
Frequently asked questions
How do I calculate square footage of a room?
Measure the length and width in feet and multiply them. A room 12 feet by 15 feet is 12 × 15 = 180 square feet. Convert inches to feet first: 6 inches is 0.5 feet, so 12 ft 6 in is 12.5 ft.
How do I find the square footage of an L-shaped room?
Split it into two rectangles, work out each one (length × width), and add them together. For example, a 10 × 12 ft section plus a 6 × 8 ft section is 120 + 48 = 168 square feet.
How much extra flooring should I buy?
Add about 10% for waste from cuts on a simple rectangular room, and around 15% for diagonal layouts, herringbone or rooms with many corners. Check the installation guide for your product.
How do I convert square feet to square meters or square yards?
Multiply square feet by 0.092903 to get square meters. Divide square feet by 9 to get square yards, which is how carpet is often priced.