Square Foot Calculator Rectangle
Calculate the square footage of any rectangle. Enter length and width in feet, inches, meters, or cm to get the area in square feet instantly.
Rectangle / Square Calculator
Enter the width and length of the rectangular area to calculate its square footage.
Dimensions update as you type.
All corners are 90° right angles.
How to Calculate Square Footage of a Rectangle
A rectangle is the most common shape found in rooms, yards, gardens, and buildings. To calculate the square footage of a rectangle, simply multiply the length by the width. This calculator handles any unit — feet, inches, meters, centimeters, or yards — and converts the result to square feet automatically.
Rectangle Area Formula
Both measurements must be in the same unit. If your measurements are in different units, convert them to feet first. The calculator above does this conversion for you automatically.
Step-by-Step Instructions
- Measure the length of the rectangular area — this is the longer side measured from one end to the other.
- Measure the width — the shorter side, perpendicular to the length.
- Multiply length × width to get the total area in square feet.
- Convert units if needed: divide inches by 12, multiply meters by 3.28084, or divide centimeters by 30.48.
Worked Examples
A bedroom measures 14 feet long by 12 feet wide.
14 ft × 12 ft = 168 square feet (15.61 sq m)
A patio measures 5 meters by 3 meters.
5 m × 3 m = 15 sq m → 15 × 10.764 = 161.46 square feet
When to Use a Rectangle Calculator
- Flooring projects — carpet, tile, hardwood, laminate square footage estimation
- Painting walls — calculate surface area for paint coverage
- Landscaping — garden beds, lawn sections, patio pavers, and deck area
- Real estate — determining property lot size and room dimensions
- Furniture planning — ensuring furniture fits within the available space
- Construction — material estimation for drywall, insulation, and roofing
Common Room Sizes in Square Feet
| Room Type | Typical Size | Square Feet |
|---|---|---|
| Small Bedroom | 10 × 10 ft | 100 sq ft |
| Standard Bedroom | 12 × 12 ft | 144 sq ft |
| Master Bedroom | 14 × 16 ft | 224 sq ft |
| Living Room | 16 × 20 ft | 320 sq ft |
| Kitchen | 12 × 16 ft | 192 sq ft |
| Bathroom | 8 × 10 ft | 80 sq ft |
| Garage (2-car) | 20 × 24 ft | 480 sq ft |
Tips for Accurate Measurements
Always measure from wall to wall for indoor spaces. Include all recesses and alcoves as separate rectangles and add them to the total. For outdoor areas, use a longer measuring tape or measuring wheel along the boundaries. When ordering materials, always round up and add 10% extra for waste and cutting.
Understanding Square Footage vs. Other Units
Square footage (ft²) is the standard unit for area in the United States. In most other countries, square meters (m²) is more common. Here are some quick conversions:
| From | To Square Feet | Multiply By |
|---|---|---|
| Square Meters | Square Feet | 10.7639 |
| Square Yards | Square Feet | 9 |
| Square Inches | Square Feet | ÷ 144 |
| Acres | Square Feet | 43,560 |
Frequently Asked Questions
How do I calculate the square footage of a rectangle? +
Multiply the length by the width. Both measurements must be in the same unit (feet). For example, a 12 ft × 10 ft room = 120 square feet.
How do I convert inches to feet for square footage? +
Divide the inch measurement by 12 to convert to feet. For example, 96 inches = 8 feet. Then multiply length × width in feet to get square feet.
How many square feet is a 10×12 room? +
A 10 ft × 12 ft room is 120 square feet. This is a common bedroom size equivalent to about 11.15 square meters.
How many square feet is a 20×20 room? +
A 20 ft × 20 ft room is 400 square feet or about 37.16 square meters. This is a typical size for a large living room or master bedroom.
How do I calculate square footage for flooring? +
Measure each room's length × width in feet, add all room areas together, then add 10% extra for waste and cutting. This gives you the total flooring material to order.
What is the difference between square feet and linear feet? +
Linear feet measures distance in one direction (a line). Square feet measures area (two dimensions — length × width). You need square feet for flooring, paint, and material estimates.
How do I find the square footage of an oddly shaped rectangular room? +
Break the room into smaller rectangles. Measure each section's length × width, calculate each area separately, then add all the areas together for the total.