Question 1

How do I calculate square footage?

Accepted Answer

For a rectangle: sq ft = length (ft) × width (ft). For a 12×15 foot room: 12 × 15 = 180 sq ft. For an L-shaped room, split into two rectangles, calculate each, and add. For a triangle: sq ft = 0.5 × base × height. For a circle: sq ft = π × radius².

Question 2

How do I calculate square footage from inches?

Accepted Answer

Convert inches to feet first: divide by 12. For a room 144 inches × 180 inches: 144/12 = 12 ft; 180/12 = 15 ft; area = 12 × 15 = 180 sq ft. Alternatively: multiply inch dimensions and divide by 144 (inches² to sq ft). 144 × 180 = 25,920 in² / 144 = 180 sq ft.

Question 3

How many square feet does 1 gallon of paint cover?

Accepted Answer

One gallon of paint typically covers 350–400 sq ft with one coat on smooth surfaces. Textured, porous, or dark surfaces may need 250–300 sq ft per gallon. For two coats (recommended for best results), double the paint needed. Always buy 10% extra for touch-ups and waste.

Question 4

How do I calculate flooring for a room with waste factor?

Accepted Answer

Add 10% waste for straight-lay flooring, 15% for diagonal patterns, and 15–20% for natural stone or highly varied wood (pattern matching). For 180 sq ft room with 10% waste: 180 × 1.10 = 198 sq ft to purchase. Most flooring is sold in boxes covering specific sq ft — divide total by box coverage and round up.

Question 5

What is the average square footage of a US home?

Accepted Answer

The median US new single-family home in 2023 is approximately 2,230 sq ft (down from a 2015 peak of ~2,690 sq ft). Average existing homes vary widely: small apartments 500–800 sq ft; average condos 900–1,200 sq ft; townhomes 1,200–1,800 sq ft; single-family homes 1,500–2,500 sq ft.

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