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Kalcufy

Square Footage Calculator

What Is Square Footage?

Square footage (sq ft) is a measurement of area — the amount of two-dimensional space a surface occupies. It's calculated by multiplying length by width when both are measured in feet. Square footage is the standard unit for measuring rooms, homes, and properties in the United States, Canada, and the United Kingdom. Whether you're buying flooring, estimating paint, pricing real estate, or planning a garden, accurate square footage calculations are essential for budgeting and ordering the right amount of materials. One square foot equals a 12-inch by 12-inch square, or approximately 0.0929 square meters.

How to Measure Square Footage

To measure square footage, start by choosing the shape that best matches your space. For rectangular rooms, simply measure the length and width in feet, then multiply them together. For circles, measure the diameter and use the formula π × (diameter/2)². For triangles, measure the base and height, then calculate ½ × base × height. For complex or irregular spaces like L-shaped rooms, divide the area into simpler shapes (rectangles, triangles), calculate each section separately, and add the results. Always measure from wall to wall at floor level, and convert all measurements to the same unit before calculating. When ordering materials, add a waste factor (typically 10%) to account for cuts, breakage, and fitting.

Frequently Asked Questions

How do I calculate the square footage of a room?

Measure the length and width of the room in feet, then multiply them together. For example, a room that is 12 feet long and 10 feet wide has an area of 120 square feet (12 × 10 = 120). For rooms that aren't perfect rectangles, break them into simpler shapes, calculate each section, and add the results.

How many square feet are in an acre?

One acre equals 43,560 square feet. To convert square feet to acres, divide by 43,560. For example, a 10,000 sq ft lot is approximately 0.23 acres. One hectare equals approximately 2.47 acres or 107,639 square feet.

How much waste factor should I add for materials?

For straight-lay flooring (hardwood, laminate, vinyl), add 10%. For diagonal layouts, add 15%. For herringbone or complex patterns, add 20%. For paint, 5% is usually sufficient. For tile, add 10-15% for cuts and breakage. Always round up to the nearest full box or gallon.

How do I convert between square feet and square meters?

To convert square feet to square meters, divide by 10.764. To convert square meters to square feet, multiply by 10.764. For example, 200 sq ft ÷ 10.764 = 18.58 m², and 50 m² × 10.764 = 538.2 sq ft.

How do I calculate the square footage of an L-shaped room?

Imagine the L as a full rectangle with a corner cut out. Calculate the full rectangle area (main length × main width), then subtract the cutout area (cutout length × cutout width). For example, a 20×15 room with an 8×6 cutout: (20 × 15) - (8 × 6) = 300 - 48 = 252 sq ft.

How much does flooring cost per square foot?

Flooring costs vary widely: vinyl/laminate runs $1-5/sq ft, hardwood $5-15/sq ft, tile $2-20/sq ft, and carpet $1-8/sq ft (materials only). Installation adds $2-8/sq ft depending on material and complexity. Always calculate total area with waste factor before getting quotes.