Square Footage Calculator
Measure area in sq ft, sq m or sq yd for any room shape, plus optional material cost.
Inputs
Multiply for identical rooms.
Optional. Enter to estimate total material cost.
Added to the area for cutting waste (typical: 10%).
Square Footage (with waste)
132.00sq ft
Square Footage (net)
120.00sq ft
Square Metres
12.26m²
Square Yards
14.67sq yd
Step by step
Single area
12 × 10 ft²
= 120.00 sq ft
Add 10% waste
120.00 × 1.10
= 132.00 sq ft
Convert to sq metres
132.00 × 0.092903
= 12.26 m²
How it works
Area is calculated for the chosen shape in the specified input unit, then converted to square feet (and optionally square metres and square yards). A waste factor is applied to account for cuts and spoilage — standard recommendations are 10% for straight-lay floors, 15% for diagonal or herringbone patterns. If a per-square-foot material cost is entered, the total cost estimate includes the waste allowance.
Formulas
Rectangle
Area = Length × Width
Circle
Area = π × radius²
Triangle
Area = ½ × base × height
Area with waste
Total area = net area × rooms × (1 + waste%)
- n
- Number of rooms
- w
- Waste percentage
Frequently Asked Questions
How do I measure an L-shaped room?
Select 'L-Shape' and measure the two rectangles that make up the L. Enter each rectangle's length and width and the calculator adds the areas.
What waste factor should I use for flooring?
10% for straight-lay patterns, 15% for diagonal or herringbone. For tile, 10–15% depending on cut complexity. The waste is built into the 'with waste' figure used for the material cost estimate.
Can I switch between feet and metres?
Yes — select your input unit (feet, inches, yards, metres, centimetres). The result is always shown in square feet and converted to square metres and square yards automatically.
How do I calculate paint coverage?
Measure the walls as rectangles. Most paint covers 350–400 sq ft per gallon. Divide your total wall area by the coverage rate to get gallons needed.