Estimate the amount of Trex decking, railing, and fasteners needed for your project.
Estimated Material Costs
Trex Decking Needed (sq ft)
Trex Railing Needed (linear ft)
Estimated Fastener Cost
Estimated Total Material Cost
Understanding Trex Deck Material Estimates
Building a deck with Trex composite materials offers durability, low maintenance, and aesthetic appeal. To accurately plan your project and budget, it's essential to estimate the quantities of decking, railing, and fasteners required. This calculator simplifies that process by using standard calculations based on your deck's dimensions.
How the Calculator Works:
Decking Area Calculation: The calculator first determines the total square footage of your deck by multiplying its length by its width (Deck Area = Length × Width). Trex decking is typically sold by linear foot, but the coverage is measured in square feet. For standard 5.5-inch wide deck boards (actual coverage per board is ~0.458 ft), we'll estimate the total square footage needed, which is a good proxy for material planning.
Railing Calculation: The total length of railing needed is directly inputted. This accounts for all sides of the deck that require a railing system. Railing costs are usually per linear foot.
Fastener Cost Estimation: Fasteners (screws, clips) are crucial for securing deck boards and railing. This calculator estimates fastener costs based on a cost per square foot of decking area. This is a simplified approach as actual fastener needs can vary based on spacing and system type.
Material Costs: The calculator uses the provided cost per linear foot for decking and railing, and the estimated fastener cost, to project the total material expense.
Key Input Considerations:
Deck Dimensions: Accurately measure the length and width of your desired deck area.
Railing Requirements: Determine which sides of the deck will need railings and measure their total combined length. Consider any built-in seating areas or steps that might alter railing needs.
Trex Product Costs: Research the current pricing for the specific Trex decking and railing lines you are interested in. Costs can vary significantly by product collection and color.
Fastener System: Different fastening systems (e.g., hidden fasteners vs. face screws) and their associated costs can impact the overall budget. The calculator uses a general estimate.
Example Calculation:
Let's say you are planning a deck that is 20 feet long and 12 feet wide, with railing on three sides totaling 64 linear feet. You find Trex decking boards cost $8.00 per linear foot and railing costs $12.00 per linear foot. Your estimated fastener cost is $1.50 per square foot.
Decking Area: 20 ft × 12 ft = 240 sq ft
Trex Decking Needed: ~240 sq ft (This is a direct estimate for coverage.)
Trex Railing Needed: 64 linear ft
Estimated Fastener Cost: 240 sq ft × $1.50/sq ft = $360
Decking Material Cost: This part requires knowing board width. If using 5.5″ boards (0.458 ft width), you'd need approx. 240 sq ft / 0.458 sq ft/linear ft = 524 linear ft. So, 524 linear ft * $8.00/linear ft = $4192. (The calculator uses a simplified sq ft estimation for decking coverage.) Let's use the calculator's approach for consistency: the calculator directly estimates coverage in sq ft. For simplicity in this example, we will use the sq ft number directly for material cost estimation assuming the user provides cost per sq ft equivalent. Assuming the $8.00/linear ft implies a certain coverage, let's adjust the calculation logic to be clearer. *Correction*: Trex boards are sold by linear foot, and their price is usually quoted per linear foot. A common board width is 5.5 inches (~0.458 ft). So, 240 sq ft needs roughly 240 / 0.458 = ~524 linear feet of decking boards. The cost would be 524 linear ft * $8.00/linear ft = $4192. The calculator will estimate total decking square footage needed.
Railing Material Cost: 64 linear ft × $12.00/linear ft = $768
This calculator provides a good starting point for budgeting your Trex deck project. Always consult with your Trex supplier or contractor for the most precise material requirements and current pricing.
function calculateDeckMaterials() {
var deckLength = parseFloat(document.getElementById("deckLength").value);
var deckWidth = parseFloat(document.getElementById("deckWidth").value);
var railingLength = parseFloat(document.getElementById("railingLength").value);
var costPerBoardFt = parseFloat(document.getElementById("costPerBoardFt").value);
var costPerRailingFt = parseFloat(document.getElementById("costPerRailingFt").value);
var fastenerCostPerSqFt = parseFloat(document.getElementById("fastenerCost").value);
var errorMessageElement = document.getElementById("errorMessage");
errorMessageElement.style.display = 'none';
errorMessageElement.innerHTML = ";
var resultContainer = document.getElementById("resultContainer");
resultContainer.style.display = 'none';
// Input validation
if (isNaN(deckLength) || deckLength <= 0 ||
isNaN(deckWidth) || deckWidth <= 0 ||
isNaN(railingLength) || railingLength < 0 || // Railing length can be 0 if not needed
isNaN(costPerBoardFt) || costPerBoardFt < 0 ||
isNaN(costPerRailingFt) || costPerRailingFt < 0 ||
isNaN(fastenerCostPerSqFt) || fastenerCostPerSqFt < 0) {
errorMessageElement.innerHTML = 'Please enter valid positive numbers for all dimensions and costs. Railing length can be zero.';
errorMessageElement.style.display = 'block';
return;
}
// Calculations
var totalDeckingSqFt = deckLength * deckWidth;
// Estimating linear feet of decking boards needed.
// Assuming standard 5.5" wide boards (~0.458 ft actual width)
// Add a small buffer for waste/cuts if necessary, but for simplicity, we'll calculate theoretical minimum.
var deckingBoardWidthFt = 0.458; // Approx. width of a 5.5" board in feet
var totalDeckingLinearFt = totalDeckingSqFt / deckingBoardWidthFt;
// A common practice is to add 5-10% for waste. Let's add 7% as a reasonable estimate.
totalDeckingLinearFt *= 1.07;
var totalDeckingCost = totalDeckingLinearFt * costPerBoardFt;
var totalRailingCost = railingLength * costPerRailingFt;
var totalFastenerCost = totalDeckingSqFt * fastenerCostPerSqFt;
var estimatedTotalCost = totalDeckingCost + totalRailingCost + totalFastenerCost;
// Display results
document.getElementById("totalDeckingSqFt").innerHTML = totalDeckingSqFt.toFixed(0); // Display as whole sq ft
// Display linear feet needed for ordering boards
var deckingLinearFtDisplay = document.createElement('span');
deckingLinearFtDisplay.className = 'result-label';
deckingLinearFtDisplay.textContent = 'Trex Decking Boards Needed (linear ft)';
document.getElementById("totalDeckingSqFt").parentNode.appendChild(document.createElement('br'));
document.getElementById("totalDeckingSqFt").parentNode.appendChild(deckingLinearFtDisplay);
document.getElementById("totalDeckingSqFt").nextElementSibling.nextElementSibling.innerHTML = totalDeckingLinearFt.toFixed(0); // Update label text for linear ft
document.getElementById("totalRailingLinearFt").innerHTML = railingLength.toFixed(0);
document.getElementById("totalFastenerCost").innerHTML = '$' + totalFastenerCost.toFixed(2);
document.getElementById("estimatedTotalCost").innerHTML = '$' + estimatedTotalCost.toFixed(2);
resultContainer.style.display = 'block';
}