This Siding Estimate Calculator is designed to provide a preliminary cost estimation for re-siding your home. Siding not only enhances your home's curb appeal but also plays a crucial role in protecting it from the elements, improving insulation, and potentially increasing its value. The total cost of a siding project is primarily influenced by the material choices, the complexity of the home's architecture, and labor rates in your area.
How the Estimate is Calculated
The calculator works by first determining the total square footage of the wall area that needs to be covered with new siding. It then subtracts the areas of windows and doors, as these typically do not require siding. Finally, it factors in the cost of materials and labor per square foot to arrive at an estimated total cost.
Key Components of the Calculation:
Wall Area: The main rectangular walls are calculated by multiplying the house's width by its height.
Formula: House Width × House Height
Gable Area: Each gable end is typically triangular. The area of a triangle is calculated as half the base (which is the width of the house) times the height of the gable. Since most houses have two gables, we calculate the area for one and assume it applies to both.
Formula for one gable: 0.5 × House Width × Gable Height Total Gable Area = 2 × (0.5 × House Width × Gable Height) = House Width × Gable Height
Total Wall & Gable Area: This is the sum of the main wall areas and the gable areas.
Formula: (2 × House Width × House Height) + (House Width × Gable Height)
(Note: This assumes two rectangular walls equal to House Width x House Height and two gables. Adjustments may be needed for complex rooflines or multiple stories where width/height might vary.)
Window & Door Area: The total area of windows and doors is calculated by summing their individual width and height products.
Formula: (Total Window Width × Total Window Height) + (Total Door Width × Total Door Height)
Siding Area to Cover: This is the total wall and gable area minus the total window and door area.
Formula: Total Wall & Gable Area – Total Window & Door Area
Material Cost: The cost of the siding material is calculated by multiplying the Siding Area to Cover by the Siding Material Cost per Sq Ft.
Formula: Siding Area to Cover × Siding Cost per Sq Ft
Labor Cost: The estimated cost for installation is calculated by multiplying the Siding Area to Cover by the Labor Cost per Sq Ft.
Formula: Siding Area to Cover × Labor Cost per Sq Ft
Total Estimated Cost: This is the sum of the Material Cost and the Labor Cost.
Formula: Material Cost + Labor Cost
Example Calculation:
Let's assume you have a house with the following dimensions:
House Width: 40 ft
House Height: 20 ft
Gable Height: 10 ft
Total Window Width: 15 ft
Total Window Height: 8 ft
Total Door Width: 6 ft
Total Door Height: 7 ft
Siding Material Cost: $3.50 per Sq Ft
Labor Cost: $4.00 per Sq Ft
Here's how the estimate would break down:
Main Wall Area: (2 × 40 ft × 20 ft) = 1600 sq ft
Gable Area: (40 ft × 10 ft) = 400 sq ft
Total Wall & Gable Area: 1600 sq ft + 400 sq ft = 2000 sq ft
Total Window Area: 15 ft × 8 ft = 120 sq ft
Total Door Area: 6 ft × 7 ft = 42 sq ft
Total Exclusion Area: 120 sq ft + 42 sq ft = 162 sq ft
Siding Area to Cover: 2000 sq ft – 162 sq ft = 1838 sq ft
Material Cost: 1838 sq ft × $3.50/sq ft = $6,433.00
Labor Cost: 1838 sq ft × $4.00/sq ft = $7,352.00
Total Estimated Cost: $6,433.00 + $7,352.00 = $13,785.00
Disclaimer: This calculator provides an estimate only. Actual costs may vary based on the specific siding material chosen, architectural complexities, removal of old siding, local labor rates, and any unforeseen issues encountered during installation. It is always recommended to obtain detailed quotes from multiple qualified siding contractors for an accurate project cost.
function calculateSidingEstimate() {
var houseWidth = parseFloat(document.getElementById("houseWidth").value);
var houseHeight = parseFloat(document.getElementById("houseHeight").value);
var gableHeight = parseFloat(document.getElementById("gableHeight").value);
var windowWidth = parseFloat(document.getElementById("windowWidth").value);
var windowHeight = parseFloat(document.getElementById("windowHeight").value);
var doorWidth = parseFloat(document.getElementById("doorWidth").value);
var doorHeight = parseFloat(document.getElementById("doorHeight").value);
var sidingCostPerSqFt = parseFloat(document.getElementById("sidingCostPerSqFt").value);
var laborCostPerSqFt = parseFloat(document.getElementById("laborCostPerSqFt").value);
var resultElement = document.getElementById("result");
resultElement.innerHTML = "; // Clear previous result
resultElement.classList.remove('visible');
// Input validation
if (isNaN(houseWidth) || houseWidth <= 0 ||
isNaN(houseHeight) || houseHeight <= 0 ||
isNaN(gableHeight) || gableHeight < 0 || // Gable height can be 0 for flat roofs
isNaN(windowWidth) || windowWidth < 0 ||
isNaN(windowHeight) || windowHeight < 0 ||
isNaN(doorWidth) || doorWidth < 0 ||
isNaN(doorHeight) || doorHeight < 0 ||
isNaN(sidingCostPerSqFt) || sidingCostPerSqFt < 0 ||
isNaN(laborCostPerSqFt) || laborCostPerSqFt < 0) {
resultElement.innerHTML = 'Please enter valid positive numbers for all fields.';
resultElement.classList.add('visible');
return;
}
// Calculate areas
var mainWallArea = 2 * houseWidth * houseHeight;
var gableArea = houseWidth * gableHeight; // Assuming 2 gables, each 0.5 * base * height
var totalWallAndGableArea = mainWallArea + gableArea;
var totalWindowArea = windowWidth * windowHeight;
var totalDoorArea = doorWidth * doorHeight;
var totalExclusionArea = totalWindowArea + totalDoorArea;
var sidingAreaToCover = totalWallAndGableArea – totalExclusionArea;
// Ensure siding area is not negative
if (sidingAreaToCover < 0) {
sidingAreaToCover = 0;
}
// Calculate costs
var materialCost = sidingAreaToCover * sidingCostPerSqFt;
var laborCost = sidingAreaToCover * laborCostPerSqFt;
var totalEstimatedCost = materialCost + laborCost;
// Format currency
var formattedMaterialCost = materialCost.toFixed(2);
var formattedLaborCost = laborCost.toFixed(2);
var formattedTotalEstimatedCost = totalEstimatedCost.toFixed(2);
var formattedSidingArea = sidingAreaToCover.toFixed(2);
resultElement.innerHTML = `$${formattedTotalEstimatedCost} Total Estimated Cost`;
resultElement.innerHTML += `Area to Cover: ${formattedSidingArea} sq ft`;
resultElement.innerHTML += `Material Cost: $${formattedMaterialCost}`;
resultElement.innerHTML += `Labor Cost: $${formattedLaborCost}`;
resultElement.classList.add('visible');
}