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Square Footage Calculator

Calculate area in square feet for rectangles, circles, and more.

Last updated: June 13, 2026

Calculator

Shape

Length

feet

Width / Radius / Height

feet

Results

Square Footage300.0 sq ft

Square Meters27.87 sq m

Acres0.0069 acres

Square Yards33.33 sq yd

How to Use This Calculator

1Select the shape of your area.
2Enter the required dimensions.
3View square footage and conversions to other units.
4Use for flooring, painting, roofing, or land measurement.

Formula Explanation

Square footage is calculated using the appropriate geometric formula for the selected shape.

Rectangle: Area = Length × Width Circle: Area = π × r² Triangle: Area = ½ × Base × Height Trapezoid: Area = ½ × (a + b) × Height

Variables:

Length/WidthDimensions for rectangular areas

RadiusHalf the diameter for circular areas

Base/HeightDimensions for triangular areas

Worked Examples

Room: 12 ft × 15 ft

1. Area = 12 × 15 = 180 sq ft

Result: 180 sq ft (20 sq yd / 16.7 sq m)

Circular patio: 10 ft diameter

1. Radius = 5 ft
2. Area = π × 5² = 78.5 sq ft

Result: 78.5 sq ft

Why Use This Calculator

Works for any common shape.
Converts between all major area units.
Essential for material ordering (flooring, paint, sod).
Saves time on real estate and renovation measurements.

336 × 280 Large Rectangle

300 × 250 Medium Rectangle

Tips & Best Practices

Measure in feet and inches, then convert — it reduces rounding errors.
For irregularly shaped rooms, divide into rectangles and add them up.
Add 10% to material orders for cuts and waste.
Double-check by measuring twice before ordering materials.

Common Mistakes to Avoid

❌ Confusing linear feet with square feet.

✅ Square footage is area (length × width). Linear feet is just length. A 10×12 room is 120 sq ft, not 22 linear ft.

❌ Forgetting to account for closets or alcoves.

✅ Measure each section separately and add them together for total square footage.

Frequently Asked Questions

How do I calculate square footage of a room?

Measure the length and width of the room in feet, then multiply them. A 12×15 room is 180 square feet. For L-shaped rooms, divide into rectangles and add.

How many square feet is an acre?

One acre is 43,560 square feet. A football field (without end zones) is about 48,000 square feet, slightly larger than an acre.

How do I convert square feet to square yards?

Divide square feet by 9. For example, 180 sq ft ÷ 9 = 20 square yards. This is useful for ordering carpet, which is often priced per square yard.

336 × 280 Large Rectangle

300 × 250 Medium Rectangle

Embed This Calculator

Add the Square Footage Calculator to your website for free. Copy the code below and paste it into your HTML.

Width

Height

<iframe src="https://redicalc.com/embed/construction/square-footage-calculator" width="100%" height="600" style="border:none;border-radius:12px;box-shadow:0 1px 3px rgba(0,0,0,0.1);" title="Square Footage Calculator — RediCalc.com" loading="lazy" allowtransparency="true"></iframe>

Preview embedFree to use · Attribution link included

Disclaimer: This calculator is provided for informational and educational purposes only. Results are estimates and should not be used as a substitute for professional advice. RediCalc.com makes no guarantees regarding the accuracy, completeness, or suitability of any calculations. Always consult a qualified professional before making financial, health, construction, or other important decisions.

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