How do you calculate square footage?

Multiply the Length in feet by the Width in feet. For example, a room that is 15 feet long by 10 feet wide is 15 × 10 = 150 square feet.

How do you convert square feet to square yards?

Divide the total square footage by 9. For example, 900 sq ft ÷ 9 = 100 square yards. Carpet is commonly sold by the square yard in the US.

How do you convert square feet to square meters?

Divide square footage by 10.764 (or multiply by 0.0929). For example, 1,000 sq ft ÷ 10.764 = 92.9 square meters.

How much waste should I add for flooring or tile?

Add 10% extra material for standard straight-lay plank flooring or tiles. Add 15% to 20% for diagonal, herringbone, or chevron patterns due to corner cuts.

How many square feet does one gallon of paint cover?

One gallon of quality interior paint covers approximately 350 to 400 square feet with a single coat.

Square Footage Calculator | Area & Cost per Sq Ft

How to Calculate Square Footage: Formulas & Practical Guide

Whether you are ordering hardwood flooring, calculating drywall sheet counts, pricing a roofing replacement, or estimating the total cost to build a house, calculating square footage (sq ft or ft²) is the fundamental starting point in construction estimating.

1. Square Footage Formula for Rectangles & Squares

For standard square or rectangular rooms, multiply length in feet by width in feet:

Square Footage = Length (ft) × Width (ft)

Example: A bedroom measuring 14 feet long by 12 feet wide has an area of 14 × 12 = 168 sq ft.

2. Calculating L-Shaped or Complex Rooms

Irregular or L-shaped living spaces should be split into smaller, separate rectangular sections (Section A and Section B). Calculate each rectangle individually and sum the totals:

Section A: 12 ft × 10 ft = 120 sq ft
Section B: 8 ft × 6 ft = 48 sq ft
Total L-Shaped Room: 120 + 48 = 168 sq ft

3. Triangular & Circular Areas

Triangular Gable / Roof: Area = (Base × Height) ÷ 2

Circular Patio / Column: Area = 3.14159 × Radius²

Area Conversion Chart

Square Feet (sq ft)	Square Yards (sq yd)	Square Meters (m²)	Flooring Boxes (20 sq ft/box)
100 sq ft	11.11 sq yd	9.29 m²	5 boxes
250 sq ft	27.78 sq yd	23.23 m²	13 boxes
500 sq ft	55.56 sq yd	46.45 m²	25 boxes
1,000 sq ft	111.11 sq yd	92.90 m²	50 boxes
1,500 sq ft	166.67 sq yd	139.35 m²	75 boxes
2,000 sq ft	222.22 sq yd	185.81 m²	100 boxes
3,000 sq ft	333.33 sq yd	278.71 m²	150 boxes

Why You Must Add a Material Waste Factor

Standard rectangular materials (such as hardwood planks, porcelain tiles, and drywall sheets) must be trimmed to fit wall contours, door openings, and room perimeters.

Straight-Lay Flooring (Hardwood, LVP, Laminate): Add 10% waste.
Diagonal or Herringbone Tile Patterns: Add 15% to 20% waste due to excessive angle cuts.
Interior Paint: Add 5% to 10% for roller absorption and touch-ups.

Square Footage Calculator

1. Add Rooms & Spaces

2. Calculated Area & Budget

Material & Coverage Estimation:

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