🏠Siding Calculator
Calculate siding needed
How to Use This Calculator
Enter Wall Dimensions
Input the height and length of your wall in feet. Measure each wall separately for accuracy. For multiple walls, calculate each wall and add the square footage together.
Calculate Siding Needs
Click "Calculate Siding" to see square feet needed (with 10% waste included) and squares. One square equals 100 square feet—the standard unit for siding sales.
Account for Openings
Subtract window and door areas from total wall area for accuracy. Standard windows are 15-25 sq ft each, doors are 20-30 sq ft each. Or calculate each wall section separately.
Order Materials
Use the square feet or squares result to order siding. Siding is typically sold by the square (100 sq ft). Add extra for corners, trim pieces, and starter strips. Order all siding from the same batch for color consistency.
Formula
Wall Area (sq ft) = Height (ft) Ă— Length (ft)
Siding Needed = Wall Area Ă— 1.10 (includes 10% waste)
Squares = Siding Needed Ă· 100
After Openings = Wall Area - (Windows + Doors) Ă— 1.10
Example 1: Standard Wall (10 ft Ă— 40 ft, no openings)
Step 1: Calculate wall area: 10 Ă— 40 = 400 sq ft
Step 2: Add waste: 400 Ă— 1.10 = 440 sq ft
Step 3: Calculate squares: 440 Ă· 100 = 4.4 squares
Step 4: Round up: 5 squares (with 10% waste)
Example 2: Wall with Openings (10 ft Ă— 40 ft, 2 windows, 1 door)
Step 1: Calculate wall area: 10 Ă— 40 = 400 sq ft
Step 2: Subtract openings: 400 - (2 Ă— 20) - (1 Ă— 25) = 400 - 40 - 25 = 335 sq ft
Step 3: Add waste: 335 Ă— 1.10 = 368.5 sq ft
Step 4: Calculate squares: 368.5 ÷ 100 = 3.7 squares → 4 squares
About Siding Calculator
The Siding Calculator is an essential tool for homeowners, contractors, builders, and DIY enthusiasts who need to accurately determine how much siding is required for their projects. This calculator eliminates guesswork by providing precise square footage and square calculations (siding is sold by the square = 100 sq ft), helping you order the right amount of materials without waste or shortages.
When to Use This Calculator
- New Siding Installation: Calculate siding needed for new home construction or additions
- Siding Replacement: Determine materials needed for replacing existing siding
- Siding Repairs: Estimate siding quantities for partial siding repairs or replacement
- Budget Planning: Calculate material costs by determining exact square footage needed
- Contractor Estimates: Quick reference for contractors bidding siding projects
Why Use Our Calculator?
- âś… Accurate Measurements: Precise square footage calculations prevent over-ordering or running short
- ✅ Squares Calculation: Shows results in squares (100 sq ft each—standard unit for siding sales)
- âś… Waste Factor: Automatically includes 10% extra for cuts, corners, and waste
- âś… Cost Planning: Helps budget accurately by determining exact material needs
- âś… Time Savings: Instant calculations eliminate manual math and measurements
- âś… Professional Results: Industry-standard formulas ensure contractor-quality estimates
Common Applications
Residential Siding: Homeowners planning new siding installations or replacing existing siding use this calculator to order the correct quantity of vinyl, fiber cement, wood, or other siding materials. Siding is typically sold by the square (100 sq ft), which this calculator helps determine accurately.
Commercial Siding: Contractors working on commercial buildings use this tool to estimate siding quantities for offices, retail spaces, and commercial buildings, ensuring sufficient materials are on-site before starting work.
DIY Projects: DIY enthusiasts planning weekend siding projects use this calculator to determine materials needed, avoiding costly mistakes from ordering too little or too much siding.
Tips for Best Results
- Measure Each Wall: Calculate each wall separately for accuracy, then add totals together
- Account for Openings: Subtract window and door areas (15-30 sq ft each) for accuracy
- Add Extra: Always add 10% extra for waste, cuts around corners, and mistakes
- Corners & Trim: Add extra siding for corner pieces, trim, starter strips, and J-channels
- Order Same Batch: Order all siding from the same batch/lot for color consistency
Frequently Asked Questions
How much siding do I need for a 10Ă—40 foot wall?
A 10Ă—40 foot wall (400 sq ft) requires approximately 440 sq ft of siding with 10% waste, or about 4.4 squares. Round up to 5 squares to ensure you have enough material. One square = 100 sq ft.
What is a square of siding?
A square equals 100 square feet. Siding is typically sold by the square (100 sq ft). For example, 400 sq ft = 4 squares. Siding packages often indicate coverage in squares for easy ordering.
Do I need to subtract windows and doors?
Yes! Subtract window and door areas from total wall area for accuracy. Standard windows are 15-25 sq ft each, doors are 20-30 sq ft each. For example, a wall with 2 windows (20 sq ft each) and 1 door (25 sq ft) = subtract 65 sq ft total.
Should I add extra siding for waste?
Yes! Always add 10% extra for waste, cuts around corners and openings, and mistakes. If you need 400 sq ft, order 440 sq ft (4.4 squares → 5 squares) to ensure you have enough material.
Do I need extra siding for corners and trim?
Yes! Add extra siding for corner pieces, J-channels, starter strips, trim pieces, and accessories. These are sold separately from siding panels. Plan for 10-15% extra for these accessories.
How much does siding cost per square?
Siding prices vary by material: vinyl $2-$7 per sq ft, fiber cement $5-$12 per sq ft, wood $8-$15 per sq ft. Installation costs $2-$8 per sq ft separately. Get quotes from contractors for accurate pricing.