Square Footage Calculator
Calculate Area for All Shapes: Rectangle, Circle, Triangle, Trapezoid & More
📏 Pro Tips for Accurate Measurements:
Measure carefully using a measuring tape or laser measurement tool. Double-check all dimensions before calculating. For irregular shapes, break them into simple shapes and calculate each separately, then add together. Include 10-15% waste allowance for material orders.
Rectangle Square Footage
✅ Rectangle Area:
Circle Square Footage
✅ Circle Area:
Triangle Square Footage (Base & Height)
✅ Triangle Area:
Trapezoid Square Footage
✅ Trapezoid Area:
Sector (Pie Slice) Square Footage
✅ Sector Area:
Ring (Annulus) Square Footage
✅ Ring Area:
🔄 Square Footage Unit Conversions
| From | To | Multiply By | Example |
|---|---|---|---|
| Square Feet | Square Yards | ÷ 9 | 900 sq ft ÷ 9 = 100 sq yards |
| Square Feet | Square Meters | × 0.092903 | 100 sq ft × 0.093 = 9.3 sq m |
| Square Meters | Square Feet | × 10.764 | 10 sq m × 10.764 = 107.6 sq ft |
| Square Feet | Square Inches | × 144 | 10 sq ft × 144 = 1,440 sq in |
| Square Inches | Square Feet | ÷ 144 | 1,440 sq in ÷ 144 = 10 sq ft |
| Square Acre | Square Feet | × 43,560 | 1 acre × 43,560 = 43,560 sq ft |
| 1 Acre | Square Meters | × 4,047 | 1 acre × 4,047 = 4,047 sq m |
📋 Common Uses for Square Footage Calculations
Painting & Surface Coating:
Professional painters quote based on square footage. Coverage: typically 300-400 sq ft per gallon of paint. Include trim, baseboards, and architectural features.
Flooring Installation:Flooring costs quoted per square foot. Add 10-15% waste for cuts and breakage. Factor in underlayment, padding, and installation labor.
Landscaping & Lawn Care:Landscape design, seeding, sod installation, and maintenance quoted per square foot. Account for walkways, planting beds, and hardscaping.
Real Estate & Property Valuation:Property value per square foot varies by location, condition, and amenities. Used for appraisals, taxes, and market comparisons.
Construction & Building:Cost per square foot includes materials, labor, and equipment. Varies widely by region, complexity, and construction type.
Roofing Installation:Roofing quoted per square (100 square feet). Account for pitch, complexity, and materials. Add waste for cutting and fit.
❓ Frequently Asked Questions
How do I calculate square footage for an irregular shape?
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Break irregular shapes into simple shapes (rectangles, circles, triangles). Calculate area for each piece using appropriate formulas. Add all areas together for total square footage. For very complex shapes, use grid method: overlay grid, count squares, calculate total area.
What's the difference between square feet and linear feet?
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Square feet measures area (2D): length × width. Linear feet measures length only (1D): single dimension. Use square feet for floor/wall coverage. Use linear feet for trim, fencing, or edge lengths. A 10 × 10 room is 100 square feet with 40 linear feet of perimeter.
How many square feet in an acre?
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1 acre = 43,560 square feet. 1 acre = 4,047 square meters. 1 acre ≈ 0.405 hectares. Used for land measurements in real estate and agriculture.
Should I add waste allowance when calculating material needed?
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Yes, always add 10-15% waste allowance. Reasons: cutting waste, mistakes, future repairs, pattern matching, and irregularities. For complex installations or premium materials, add 15-20%. Better to have extra than run short mid-project.
How do I calculate square footage for my house?
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Measure each room's length and width, calculate area (length × width). Add all room areas together for total. For multi-level homes, calculate each floor separately. Note: appraisers typically exclude unfinished basements, attics, and garages. Official appraisals measure from exterior dimensions and follow specific guidelines.
What formula do I use for a circle?
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Area = π × r² where r is radius. If you have diameter, divide by 2 first. Example: 20-foot diameter ÷ 2 = 10-foot radius. Then: 3.14159 × 10² ≈ 314.2 square feet.
How do I convert between square meters and square feet?
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Square meters to square feet: multiply by 10.764. Square feet to square meters: multiply by 0.092903. Example: 100 sq m × 10.764 = 1,076.4 sq ft. Or: 1,000 sq ft × 0.093 = 93 sq m.
What is cost per square foot used for?
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Cost per square foot estimates project expenses. Multiply total square footage by cost per unit to get total project cost. Used for painting, flooring, landscaping, construction, and real estate. Prices vary by location, materials, complexity, and market conditions.