Square Footage Calculator
Calculate the square footage of any area. Supports rectangles, squares, circles, triangles, and trapezoids. Converts between square feet, square meters, square yards, acres, and more.
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Whether you're planning a home renovation, evaluating a property purchase, or estimating material costs, knowing how to calculate square footage accurately is an essential skill. Our square footage calculator simplifies this process by supporting multiple shapes and automatic unit conversions, making it perfect for homeowners, contractors, real estate professionals, and DIY enthusiasts alike.
Square footage represents the total two-dimensional area of a space, measured in square feet. This measurement is the foundation for countless decisions in real estate transactions, construction projects, interior design planning, and property assessments. Understanding how to calculate it correctly can save you time, money, and prevent costly mistakes.
How to Calculate Square Footage
Calculating square footage is fundamentally about finding the area of a two-dimensional space. The basic principle involves multiplying length by width for rectangular spaces, but different shapes require different approaches. The key is to ensure all measurements are in the same unit before performing calculations.
For the simplest case—a rectangular room—you multiply the length by the width. If your room measures 12 feet long and 10 feet wide, the square footage is 12 × 10 = 120 square feet. This straightforward multiplication works because you're essentially counting how many one-foot-by-one-foot squares fit into your space.
When dealing with non-rectangular spaces, you'll need to apply shape-specific formulas or break complex areas into simpler geometric shapes. The calculator above handles this automatically, but understanding the underlying math helps you verify results and tackle unique situations.
Steps to Calculate Square Feet
- Choose your measurement tool: Use a tape measure, laser measure, or measuring wheel depending on the size of the space. For accuracy, measure at floor level.
- Measure the length: Measure the longest dimension of the space from one wall to the opposite wall. Record this measurement in feet and inches, or convert to decimal feet.
- Measure the width: Measure the perpendicular dimension. For rectangular spaces, this is the shorter side, but always measure the full width at the widest point.
- Convert to consistent units: If you measured in inches, convert to feet by dividing by 12. For example, 6 inches = 0.5 feet. Ensure both measurements use the same unit.
- Multiply length by width: For rectangular spaces, multiply the length by the width. The result is your square footage.
- Account for irregular areas: If the space has alcoves, closets, or irregular sections, calculate each separately and add them together.
- Verify your calculation: Double-check your measurements and math. For important projects, measure twice to ensure accuracy.
Square Footage Formulas
Different geometric shapes require specific formulas to calculate their area. Here are the most commonly used formulas for calculating square footage:
Example: 15 ft × 12 ft = 180 sq ft
Example: 10 ft × 10 ft = 100 sq ft
Example: π × (5 ft)² = 78.54 sq ft
Example: (8 ft × 6 ft) ÷ 2 = 24 sq ft
Example: ((10 ft + 8 ft) ÷ 2) × 5 ft = 45 sq ft
For spaces with multiple shapes, calculate each section separately using the appropriate formula, then sum all the areas to get the total square footage.
How to Find the Square Footage of a Room
Measuring a room's square footage requires careful attention to detail. Start by clearing the room of furniture and obstacles to get accurate wall-to-wall measurements. Use a quality tape measure that's long enough to span the entire dimension without needing multiple measurements.
For standard rectangular rooms, measure the length and width at floor level, ensuring your tape measure is straight and parallel to the walls. Measure to the nearest inch, then convert to decimal feet for easier calculation. If the room has built-in features like bay windows or alcoves, measure the main rectangular area first, then add the square footage of any additional spaces.
Quick Room Measurement Tips:
- Measure at the widest points, not at narrow sections
- Include closets and storage areas in your measurements
- For L-shaped rooms, divide into two rectangles and add the areas
- Don't subtract for doorways or openings unless calculating usable floor space
- Record measurements immediately to avoid forgetting or mixing up numbers
How to Calculate the Square Feet of a Home or Residence
Calculating the total square footage of an entire home involves measuring each room and summing the results. This process is more comprehensive than measuring a single room and requires systematic organization to ensure accuracy.
Begin by creating a floor plan or sketch of your home, labeling each room. Measure each room individually using the methods described above, recording the square footage for each space. Include all finished living areas: bedrooms, bathrooms, living rooms, kitchens, dining areas, hallways, and finished basements or attics.
What to Include:
- All finished rooms with heating, cooling, and finished walls
- Finished basements and attics that meet local building codes
- Enclosed porches and sunrooms that are climate-controlled
- Garages converted to living spaces (if permitted and finished)
What to Exclude:
- Unfinished basements, attics, or storage areas
- Garages, carports, and outdoor storage structures
- Open patios, decks, and porches (unless enclosed and finished)
- Unfinished areas used only for storage or utilities
After measuring each room, add all the individual square footages together. For multi-story homes, calculate each floor separately, then sum the totals. This gives you the gross living area, which is the standard measurement used in real estate listings and appraisals.
How to Calculate Price per Sq Ft
Price per square foot is a valuable metric for comparing properties and understanding real estate values. It's calculated by dividing the total price of a property by its total square footage.
Formula:
Price per Square Foot = Total Property Price ÷ Total Square FootageExample:
If a home costs $350,000 and has 2,000 square feet:
$350,000 ÷ 2,000 sq ft = $175 per square foot
This calculation helps you compare properties of different sizes on an equal basis. A smaller home might have a higher price per square foot due to fixed costs like kitchens and bathrooms, while larger homes often have lower per-square-foot prices. Use this metric alongside other factors like location, condition, and features when evaluating properties.
When calculating price per square foot for rental properties, use the annual rent divided by the square footage to find the rent per square foot. This helps compare rental rates across different property sizes and locations.
How to Convert to Square Feet
Converting measurements from other units to square feet is essential when working with mixed units or international measurements. Here are the most common conversion factors you'll need:
Example: 50 sq m × 10.764 = 538.2 sq ft
Example: 100 sq yd × 9 = 900 sq ft
Example: 1,440 sq in ÷ 144 = 10 sq ft
Example: 0.5 acres × 43,560 = 21,780 sq ft
Example: 1 hectare × 107,639 = 107,639 sq ft
When converting linear measurements before calculating area, convert to feet first. For example, if you have measurements in inches, divide by 12 to get feet, then multiply length by width. If working with meters, multiply by 3.28084 to convert to feet before calculating the area.
Our calculator automatically handles these conversions, allowing you to input measurements in feet, inches, meters, yards, or centimeters, and receive results in multiple units including square feet, square meters, square yards, acres, and hectares.
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