Calculate Square Footage
Select your room shape and enter dimensions to calculate area in square feet.
Rectangular Room
L-Shaped Room (Two Rectangles)
Break your L-shaped room into two rectangles.
Section 1
Section 2
Circular Room
Tip: If you have diameter, divide by 2 to get radius
Irregular Room (Multiple Sections)
Add rectangular sections one at a time. The total will be calculated automatically.
How to Calculate Square Footage
Square footage measures the area of a space in square feet, commonly used for flooring, painting, real estate, and construction projects in the United States.
Basic Formula for Rectangular Rooms
Square Footage = Length (ft) × Width (ft)
For example, a room that measures 12 feet long by 10 feet wide has 120 square feet of floor area (12 × 10 = 120 sq ft).
Converting to Square Feet
- From inches: Divide by 144 (12 × 12). A 24" × 36" area = (24 × 36) ÷ 144 = 6 sq ft
- From yards: Multiply by 9. A 3 yd × 4 yd area = (3 × 4) × 9 = 108 sq ft
- From meters: Multiply by 10.764. A 5 m × 4 m area = (5 × 4) × 10.764 = 215.28 sq ft
Tips for Accurate Measurements
- Measure in the same units — Keep all measurements in feet (or convert to feet first)
- For L-shaped rooms — Break into two rectangles, calculate each, then add together
- Irregular rooms — Divide into simple rectangles, calculate each section, sum the total
- Add 5-10% for waste — When ordering flooring or materials, account for cuts and mistakes
- Measure wall-to-wall — Include closets and alcoves in your room measurement
Common Applications
| Project | What to Measure | Waste Factor |
|---|---|---|
| Flooring / Carpet | Floor area only | Add 10% |
| Wall Paint | Perimeter × height, minus doors/windows | 350-400 sq ft per gallon |
| Tiles | Floor or wall area | Add 10-15% |
| Hardwood | Floor area | Add 5-10% |
Frequently Asked Questions
How do I calculate square footage of a room?
How many square feet is a 10x12 room?
How do I convert inches to square feet?
How do I calculate square footage for irregular rooms?
How many square feet of flooring do I need?
How much paint do I need for a room?
What is the difference between square feet and linear feet?
How many square feet is a 12x12 tile?
How do I calculate square footage of a circle?
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are estimates and may vary based on actual conditions.
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Square Footage Calculator FAQ
How do I calculate square footage of a room?
Measure the length and width of the room in feet, then multiply them together. For example, a room that is 12 feet long and 10 feet wide has 120 square feet (12 × 10 = 120 sq ft).
How many square feet is a 10x12 room?
A 10x12 room is 120 square feet. Multiply the length (10 feet) by the width (12 feet) to get 120 sq ft.
How do I convert inches to square feet?
First convert your measurements to feet (divide inches by 12), then multiply length by width. Or multiply length in inches by width in inches, then divide by 144 to get square feet.
How do I calculate square footage for irregular rooms?
Break the irregular room into rectangles or other simple shapes. Calculate the square footage of each section separately, then add them together. For L-shaped rooms, treat them as two rectangles.
How many square feet of flooring do I need?
Calculate the room's square footage, then add 5-10% extra for waste, cuts, and mistakes. For example, if your room is 200 sq ft, order 210-220 sq ft of flooring material.
How much paint do I need for a room?
One gallon of paint typically covers 350-400 square feet of wall space. Calculate total wall area (perimeter × wall height), subtract windows and doors, then divide by 350 to estimate gallons needed.
What is the difference between square feet and linear feet?
Square feet measures area (length × width) in a two-dimensional space. Linear feet measures distance in one dimension only. You need square feet for flooring, carpeting, and painting coverage.
How many square feet is a 12x12 tile?
A 12-inch by 12-inch tile is 1 square foot. To find how many tiles you need, simply divide your room's square footage by 1 (or just use the same number).
How do I calculate square footage of a circle?
Measure the radius (distance from center to edge) in feet. Square it, then multiply by π (3.14159). Formula: Area = π × radius². A circular room with 10-foot radius has about 314 square feet.