Square Footage Calculator
Calculate square footage from length and width in feet and inches. Get area in ft², yd² and m², plus optional material cost, with the formula and steps shown.
Updated 2026-06-14 · Free · No sign-up · Runs privately in your browser
Show the formula & steps
How the Square Footage Calculator Works
This calculator finds the area of a rectangular space in square feet, square yards and square meters. Enter the length and width in feet and inches, and it returns the total instantly. Add a quantity to total several identical areas, or a price per square foot to estimate material cost.
The Formula
For any rectangle:
Square footage = length (ft) × width (ft)
If your tape measure reads feet and inches, convert the inches to decimal feet first:
decimal feet = whole feet + inches ÷ 12
So 10 ft 6 in becomes 10 + 6 ÷ 12 = 10.5 ft.
Worked Example
For a room measured at 12 ft long and 10 ft 6 in wide:
- Width = 10 + 6 ÷ 12 = 10.5 ft
- Area = 12 × 10.5 = 126 ft²
- Square yards = 126 ÷ 9 = 14 yd²
- Square meters = 126 × 0.092903 = ≈ 11.71 m²
At a flooring price of $4.50 per ft², the material cost is 126 × 4.50 = $567 before waste.
Measuring Irregular Rooms
For an L-shaped or stepped room, divide the floor into rectangles, calculate each one separately, and add the results. For closets, bay windows or alcoves, measure them as their own small rectangles and include them in the total.
Why Square Footage Matters
Knowing the exact area lets you:
- Buy the right amount of flooring, tile, paint or sod without overspending or running short.
- Price a job when materials and labor are quoted per square foot.
- Compare property sizes on a consistent basis.
Always add 5 to 10 percent extra material to cover cuts, breakage and waste, especially for tile and hardwood laid on a diagonal.
| Room size | Square footage |
|---|---|
| 10 × 10 ft | 100 ft² |
| 12 × 12 ft | 144 ft² |
| 12 × 10 ft 6 in | 126 ft² |
| 20 × 15 ft | 300 ft² |
Frequently asked questions
How do I calculate square footage?+
Multiply the length by the width, both measured in feet. A room 12 ft long and 10 ft wide is 12 × 10 = 120 square feet. If your measurements include inches, divide the inches by 12 first and add them to the feet before multiplying.
How do I find square footage with measurements in feet and inches?+
Convert each measurement to decimal feet by dividing the inches by 12, then multiply. A wall 10 ft 6 in wide is 10 + 6 ÷ 12 = 10.5 ft. Multiply that decimal length by the decimal width to get the area in square feet.
How many square feet is a 12x12 room?+
A 12 ft by 12 ft room is 12 × 12 = 144 square feet. For an L-shaped or irregular space, split it into rectangles, find the square footage of each, and add the results together.
How do I convert square feet to square yards or square meters?+
Divide square feet by 9 to get square yards, since one square yard equals 9 square feet. To get square meters, multiply square feet by 0.092903, because one square foot equals 0.092903 square meters.
How do I estimate flooring cost from square footage?+
Multiply the total square footage by the price per square foot. For 120 ft² of flooring at $4.50 per ft², the cost is 120 × 4.50 = $540 before waste. Add 5 to 10 percent extra to cover cuts and waste.