Square Footage Calculator
Calculate area for rooms, properties, and spaces
All Area Units
What is Square Footage?
Square footage is a measurement of area expressed in square feet. It represents the total area of a flat surface or space, calculated by multiplying length by width. This measurement is essential for real estate, construction, interior design, and many other applications.
Common Use Cases
Real Estate
Property listings, home valuations, and space comparisons for buying or selling decisions.
Flooring & Painting
Estimate materials needed for flooring, carpet, tile, paint, and wall coverings.
HVAC Sizing
Determine appropriate heating and cooling system capacity for optimal climate control.
Construction & Renovation
Plan building materials, estimate costs, and design space layouts for projects.
Interior Design
Space planning, furniture arrangement, and room optimization for functionality and aesthetics.
Landscaping & Gardening
Calculate lawn area, garden plots, and outdoor space planning for landscaping projects.
How to Use the Calculator
Step 1: Choose Your Units
Select feet, inches, meters, or centimeters based on your preference and measurements.
Step 2: Add Room Names
Label each space you're measuring for easy identification and organization.
Step 3: Select Room Shape
Choose rectangle, circle, or triangle to match your space's actual shape.
Step 4: Enter Dimensions
Input the required measurements based on the selected shape (length/width, radius, or base/height).
Step 5: Add Multiple Rooms
Use the "Add Room" button to calculate total square footage for multiple spaces.
Step 6: Review Results
See individual room areas and total square footage in various units (sq ft, sq m, etc.).
Pro Measurement Tips
Use a Quality Measuring Tool
Invest in a good tape measure or laser measure for accuracy. Digital tools reduce human error.
Measure Twice, Calculate Once
Double-check all measurements before calculating to avoid costly material estimation errors.
Account for Irregular Shapes
Break complex rooms into simpler shapes (rectangles, triangles) and add the areas together.
Add 10-15% for Waste
When buying materials, add extra for cutting waste, mistakes, and future repairs.
Consider Room Function
Different uses may require different measurements (gross vs. net area for living vs. storage).
Document Your Measurements
Keep written records with room names, dimensions, and dates for future reference.
Room Shapes & Formulas
Rectangle/Square
Formula: Length × Width
Most common room shape. Measure the longest and widest points for accuracy.
Circle
Formula: π × Radius²
For round rooms, patios, or curved spaces. Measure from center to edge for radius.
Triangle
Formula: (Base × Height) ÷ 2
For triangular spaces or peaked areas. Height must be perpendicular to base.
Accurate Measurement Tips
Measure at Floor Level
Take measurements at floor level where the area calculation matters most for flooring and furniture.
Account for Obstacles
Subtract areas for permanent fixtures like built-ins, fireplaces, or large appliances.
Use Consistent Units
Stick to one unit of measurement throughout to avoid conversion errors and confusion.
Get Help for Large Areas
Have someone hold the other end of the tape measure for long distances and better accuracy.
Check for Square Corners
Verify corners are actually 90 degrees, especially in older buildings with settling issues.
Measure Multiple Times
Take measurements several times and use the average for critical calculations and expensive materials.
Space Planning Guidelines
Living Room
Plan 10-25 sq ft per person. Minimum 150 sq ft for comfortable seating and traffic flow.
Master Bedroom
Aim for 200-300 sq ft minimum. Include space for bed, dressers, and comfortable walkways.
Kitchen
Plan 75-100 sq ft minimum, with work triangle between sink, stove, and refrigerator under 26 feet.
Bathroom
Powder rooms need 18-20 sq ft minimum. Full bathrooms require 40-60 sq ft for comfort.
Home Office
Allow 50-100 sq ft per person, with enough space for desk, chair, and storage.
Dining Room
Plan 10-12 sq ft per person seated. Allow 36 inches between table edge and wall.
Cost Estimation by Square Footage
Flooring Materials
Carpet: $2-8/sq ft, Hardwood: $6-20/sq ft, Tile: $3-15/sq ft, Vinyl: $1-7/sq ft installed.
Paint & Wall Coverings
Interior paint: $1-3/sq ft, Wallpaper: $2-10/sq ft, Textured finishes: $3-8/sq ft including labor.
HVAC Systems
Central air: $3-7/sq ft, Ductwork: $2-5/sq ft, Radiant heating: $6-15/sq ft of coverage area.
Construction Costs
Basic construction: $100-200/sq ft, Mid-range: $150-300/sq ft, High-end: $250-500+/sq ft.
Landscaping
Basic lawn: $0.50-2/sq ft, Decorative landscaping: $5-20/sq ft, Hardscaping: $10-50/sq ft.
Roofing Materials
Asphalt shingles: $3-7/sq ft, Metal roofing: $5-12/sq ft, Slate/tile: $8-20/sq ft installed.
Common Measurement Mistakes
Mixing Units of Measurement
Consequence: Calculation errors leading to massive over or under-ordering of materials.
Measuring to Baseboards Instead of Walls
Consequence: Underestimating actual floor area, resulting in insufficient materials.
Not Accounting for Doorways and Windows
Consequence: Overestimating wall area for paint or wallpaper, wasting money on excess materials.
Assuming All Corners Are 90 Degrees
Consequence: Inaccurate measurements in older or settling buildings with non-square corners.
Forgetting to Add Waste Factor
Consequence: Running short on materials during installation, causing delays and color matching issues.
Measuring Only Once
Consequence: Human error in measurement leading to expensive ordering mistakes and project delays.
Square Footage Myths vs Reality
Myth: All rooms are perfectly rectangular
Reality: Many rooms have alcoves, angled walls, or irregular shapes that require careful measurement.
Myth: Bigger always means more valuable
Reality: Layout efficiency and functionality matter more than raw square footage for livability.
Myth: You can eyeball measurements accurately
Reality: Human perception is notoriously unreliable for spatial measurements without proper tools.
Myth: All square feet are equal
Reality: Location, ceiling height, natural light, and functionality significantly affect value per square foot.
Professional Applications
Architecture & Engineering
Building design, structural load calculations, space programming, and building code compliance.
Real Estate & Appraisal
Property valuations, comparable sales analysis, investment property assessment, and market analysis.
Construction Management
Material quantity estimation, cost budgeting, project scheduling, and contractor bidding processes.
Interior Design
Space planning, furniture selection, lighting design, and workflow optimization for commercial spaces.
Facilities Management
Space utilization analysis, cleaning schedules, HVAC load calculations, and maintenance planning.
Insurance & Risk Assessment
Coverage calculations, replacement cost estimation, risk evaluation, and claims processing.
Frequently Asked Questions
Do I include closets in room square footage?
Yes, closets are typically included in room square footage as they are part of the usable living space.
How do I measure irregular shaped rooms?
Break the room into simple shapes (rectangles, triangles), calculate each area separately, then add them together.
Should I subtract area for built-in furniture?
For flooring calculations, yes. For real estate listings, built-ins are usually included in total square footage.
What's the difference between gross and net square footage?
Gross includes all space within exterior walls. Net excludes wall thickness, mechanical spaces, and structural elements.
How much extra material should I order?
Add 10-15% for most materials to account for cutting waste, mistakes, and future repairs or replacements.
Can I use this calculator for outdoor spaces?
Absolutely! It works for patios, decks, gardens, driveways, and any flat outdoor area you need to measure.
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