Square Footage Calculator
Add rectangular rooms. Paste feet + inches.
Length × width, with the units handled first
Measure each rectangular section along its inside edges. Enter its length and width in the same default unit, or type a unit with each value. The tool accepts feet, inches, meters and centimeters. Explicit unit labels override the default for that measurement.
Area in ft² = length in feet × width in feet. There are 12 inches in a foot and exactly 0.3048 meters in a foot. Therefore, 1 ft² is 0.09290304 m². Linear feet measure distance; square feet measure area. The two are not interchangeable without another dimension.
Room area examples
| Length × width | Area |
|---|---|
| 12 ft × 10 ft | 120 ft² |
| 12 ft 6 in × 10 ft | 125 ft² |
| 4 m × 3 m | 12 m² ≈ 129.166925 ft² |
| 125 ft² room + 80 ft² room | 205 ft² total |
Combine rooms without counting the same space twice
Add different rooms or split an L-shaped space into non-overlapping rectangles. Each row keeps its own dimensions; you do not need to replace one result or add figures in another calculator. Copy breakdown includes all rectangular sections, their areas, the combined total and any separate material allowance.
Room area versus material quantity
The main result is measured area. Extra material allowance starts at 0%; enter a percentage only if you want that separate estimate. The tool does not choose a waste percentage, round up to full flooring packages or model cuts. Check the actual material and layout before ordering.
All calculations run in your browser. Results display up to six decimal places; that does not make rough measurements more precise. This is a practical rectangle-area calculator, not a survey, appraisal or certification of a property's legally defined floor area.
Frequently asked questions
How do I calculate square footage?
For a rectangle, multiply its length in feet by its width in feet. A room 12 feet 6 inches long and 10 feet wide is 12.5 × 10 = 125 square feet. Add separate, non-overlapping rectangular areas to find a combined total.
Can I type feet and inches together?
Yes. Enter 12 ft 6 in or 12'6" directly. The tool converts the measurement to feet before multiplying. Decimal and fractional lengths are also supported; plain numbers use the selected default unit.
How do I add more than one room?
Choose Add room and enter the next room's length and width. The total includes every completed room, with a separate breakdown you can copy. Up to 20 rectangles are supported; an incomplete room must be filled in or removed before a final total is shown.
Can I calculate an L-shaped room?
Split the room into two rectangles that do not overlap, measure each rectangle and add them as separate rooms. Do not enter the full outer rectangle and then add the smaller section again. Circles, curved walls and irregular polygons are not calculated directly.
Does extra material allowance change the room area?
No. It shows a separate quantity equal to the measured area multiplied by 1 plus your chosen extra percentage. For 200 square feet and 10% extra, the material allowance total is 220 square feet. Package sizes, installation patterns and required cuts are not calculated.