Square Footage Calculator
Calculate square footage for rectangular, circular, or triangular spaces with waste percentage and material cost.
Privacy First: 100% Client-Side Processing
Processed in your browser. Files are never uploaded.
How to Use the Square Footage Calculator
- 1Choose your area shape: Rectangle / Box, Circle, or Triangle.
- 2Enter the length and width dimensions in your preferred unit (feet, inches, meters).
- 3Specify an optional waste margin percentage (typically 10% for tile or hardwood).
- 4Optionally enter cost per square foot to calculate project material expenditure.
Formula & How It Works
Area & Waste Calculation Formula
For a rectangular area, square footage is length multiplied by width. When adding a waste percentage (w%), the final required area accounts for cutting scraps and pattern matching.
Worked Examples
Standard Bedroom Flooring
Input: 12 ft length × 14 ft width with 10% waste
Explanation: 12 × 14 = 168 sq ft. Adding 10% waste (16.8 sq ft) equals 184.8 sq ft.
Circular Patio
Input: Diameter = 16 ft
Explanation: Area = π × (radius)² = π × (8)² ≈ 201.06 sq ft.
Frequently Asked Questions
How do I calculate square footage if dimensions are in inches?▼
Convert inches to feet by dividing by 12, or multiply length in inches by width in inches and divide the product by 144.
How much waste should I add for flooring?▼
Most contractors recommend adding 10% waste for standard layout tile and hardwood, or 15% for herringbone or diagonal patterns.
Can I calculate multiple rooms together?▼
Yes, you can add multiple room sections to calculate your home's total combined square footage.
How do I convert square feet to square yards for carpet?▼
Divide total square feet by 9 (since 1 square yard equals 9 square feet).
Related Online Tools
Explore complementary calculators and converters with instant client-side execution
Cubic Feet Calculator
Calculate 3D volume in cubic feet from length, width, and height with multi-unit support.
Cubic Yard Calculator
Calculate cubic yards for concrete pours, topsoil, mulch, and site excavation.
Gravel Calculator
Estimate gravel volume in cubic yards and weight in tons for driveways, landscaping, and foundation pads.
Board Foot Calculator
Calculate board feet (FBM) for hardwood and dimensional lumber with cost estimates.
Stair Calculator
Calculate number of risers, tread depth, stair stringer length, and incline angle conforming to building code.
Asphalt Calculator
Calculate asphalt tons and paving volume for driveways, roads, and resurfacing projects.
Explore Other Tool Categories
Browse our full collection of 50 free web utilities
Unit Converters
Exact metric & imperial conversions for weight, length, temperature & volume.
Math & Education
Percentage changes, fractions, square roots, geometry & statistics.
Date & Time
Calendar arithmetic, business day intervals, stopwatch & multi-counter.
Finance
Discount savings, markup, profit margins, CD returns & overtime pay.