Siding Calculator
Calculate how much siding you need for your home, including J-channel, corner posts, and starter strips. Supports vinyl, wood, fiber cement, and metal siding.
Wall Dimensions
Openings
Siding Material
Your Results Will Appear Here
Enter your wall dimensions and siding type, then click “Calculate” to see how much siding you need.
Top-Rated Siding Materials & Tools
Hand-picked products to help you get the best results on your project.
Georgia-Pacific
Georgia-Pacific Vinyl Siding, Double 4" Clapboard
- ✓UV resistant
- ✓Low maintenance
- ✓Limited lifetime warranty
James Hardie
James Hardie HardiePlank Fiber Cement Siding
- ✓Fire resistant
- ✓Termite proof
- ✓30-year warranty
LP
LP SmartSide Engineered Wood Siding
- ✓SmartGuard treatment
- ✓Paintable
- ✓Impact resistant
Malco
Malco SRT2 Vinyl Siding Removal Tool
- ✓Zip tool design
- ✓Easy panel removal
- ✓Hardened steel
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How to Use This Siding Calculator
Step 1: Measure Walls
Measure the height of your walls and the total perimeter of your home. Add gable end square footage separately for accurate coverage.
Step 2: Count Openings
Count all doors and windows. The calculator subtracts standard areas (20 sq ft per door, 15 sq ft per window) from the total wall area.
Step 3: Choose Material
Select vinyl, wood lap, fiber cement, or metal siding. Each material has different costs per square and installation requirements.
Step 4: Review Options
The calculator automatically estimates J-channel for openings, corner posts, and starter strips based on your measurements.
Step 5: Get Results
Click Calculate to see siding squares, accessories, and cost estimates. Copy or print results for your contractor or hardware store.
Understanding Siding Materials
Material Comparison
| Material | Cost/Sq | Lifespan | Maintenance |
|---|---|---|---|
| Vinyl | ~$90 | 20–40 years | Very low |
| Wood Lap | ~$100 | 15–40 years | High (paint every 5–7 yrs) |
| Fiber Cement | ~$130 | 50+ years | Low (paint every 10–15 yrs) |
| Metal | ~$120 | 40–70 years | Very low |
What Are Siding Squares?
Like roofing, siding is measured in “squares”—each square equals 100 sq ft of coverage. Siding is sold by the carton, with each carton covering approximately 2 squares (200 sq ft) for vinyl, or varies by product for other materials. Always add 10% for waste and cutting around openings.
Pro Tips for Siding Installation
Start from Bottom, Work Up with Each Row Overlapping
Install the starter strip at the bottom first, then work upward. Each row locks into the one below and overlaps, creating a weather-tight seal. Use a level every few rows to ensure straight lines.
Leave 1/4 Inch Gap at Trim for Expansion
Vinyl siding expands and contracts with temperature changes. Leave 1/4 inch clearance at all ends where siding meets trim, J-channel, or corners. This prevents buckling in summer heat.
Don’t Nail Siding Tight — Allow Movement
Leave a 1/32 inch gap between the nail head and the siding nailing flange. Nailing too tight restricts thermal movement and causes wavy, buckled siding. Center nails in the slot for maximum movement.
Flash Around All Windows and Doors Before Siding
Install flexible flashing tape around all window and door openings before siding. This creates a watertight seal behind the J-channel and prevents water intrusion into the wall cavity.
Fiber Cement Requires a Special Blade to Cut
Never use standard wood-cutting blades on fiber cement—it creates silica dust. Use a fiber cement shear, a circular saw with a fiber cement blade, or score-and-snap tools. Always wear a dust mask when cutting.
Frequently Asked Questions
A 1,500 sq ft house typically needs 15–20 squares of siding, depending on wall height, number of windows and doors, and gable ends. Our calculator subtracts openings and adds 10% waste for an accurate material estimate.
Vinyl siding is cheaper ($3–$7/sq ft installed), low maintenance, and easy to install. Fiber cement is more durable ($6–$12/sq ft installed), fire resistant, and looks more like real wood. Fiber cement lasts 50+ years vs 20–40 years for vinyl. Choose based on your budget and desired longevity.
Vinyl siding lasts 20–40 years. Fiber cement (James Hardie) lasts 50+ years. Engineered wood lasts 20–30 years. Metal siding can last 40–70 years. Lifespan depends on climate, installation quality, and maintenance.
You can install new siding over flat wood siding, but not over damaged, warped, or deteriorating siding. Removing old siding first lets you inspect sheathing for water damage and install proper house wrap. Most professionals recommend removal for best results.
From outside to inside: siding, house wrap (weather barrier), sheathing (plywood or OSB), insulation between studs, vapor barrier, and interior drywall. Each layer serves a specific purpose in protecting your home from moisture, wind, and heat loss.
Material costs range from $3–$12 per square foot depending on type: vinyl ($3–$7), engineered wood ($5–$9), fiber cement ($6–$12), and metal ($7–$15). Professional installation adds $2–$5 per sq ft. A typical 1,500 sq ft house costs $7,500–$25,000 total for materials and labor.