Square Feet Calculator
Free and simple, also called a square footage calculator. Type the length and width, get the square feet right away. No sign-up, no email.
Calculate Square Feet
How to Use: 3 Easy Steps
Step 1: Measure the length and width of your room or area with a tape.
Step 2: Type the numbers above and pick the unit (feet, inches, yards or meters).
Step 3: Press Calculate. You get square feet, square yards, square meters, and the cost, if you added a price.
Square Footage Formula: How to Calculate Square Feet
Square Feet = Length × Width
Example: a room is 12 feet long and 10 feet wide.
12 × 10 = 120 square feet.
For a circle: Square Feet = 3.1416 × (Diameter ÷ 2) × (Diameter ÷ 2).
For a triangle: Square Feet = (Base × Height) ÷ 2.
Ready Answers for Common Sizes
| Size (ft) | Square Feet | Common Use |
|---|---|---|
| 10 × 10 | 100 sq ft | Small bedroom, shed floor |
| 12 × 12 | 144 sq ft | Bedroom, patio slab |
| 12 × 20 | 240 sq ft | Living room, driveway part |
| 20 × 20 | 400 sq ft | Garage, big deck |
| 20 × 40 | 800 sq ft | Small house floor |
Common Mistakes to Avoid
1. Mixing units. If length is in feet, width must also be in feet, or use the unit option above, it fixes it for you.
2. Forgetting extra material. For flooring or tiles, buy about 10% extra. Cutting and small mistakes always waste some material.
3. Odd-shape rooms. If your room is not a simple rectangle, split it into 2 or 3 rectangles, calculate each one, and add them.
Questions People Ask
How do I calculate square feet?
Multiply the length by the width. Both numbers must be in feet. Example: 14 × 11 = 154 square feet.
How many square feet is a 12×12 room?
12 × 12 = 144 square feet.
How do I change square feet into square meters?
Divide the square feet by 10.764. Example: 120 sq ft ÷ 10.764 = about 11.15 square meters. This calculator shows it for you.
My measurements are in inches. What do I do?
Pick “Inches” in the unit option above the Calculate button, or divide your inches by 12 to get feet first.
How much extra flooring or tile should I buy?
Most people buy 10% extra for cuts and mistakes. For a 200 sq ft floor, plan for about 220 sq ft of material.
How do I calculate the square feet of a whole house?
Do it room by room. Calculate each room (length × width), then add all the rooms together. Example: living room 240 + bedroom 144 + kitchen 120 = 504 square feet for those three rooms.
Is a square feet calculator the same as a square footage calculator?
Yes, both names mean the same tool. People search both ways, and both use the same formula: length × width.
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