.calculator-container {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background-color: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
}
.calc-box {
background: #ffffff;
padding: 25px;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
margin-bottom: 30px;
}
.calc-title {
text-align: center;
color: #333;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #555;
}
.input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #0073aa;
outline: none;
}
.calc-btn {
width: 100%;
padding: 14px;
background-color: #0073aa;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background 0.3s;
}
.calc-btn:hover {
background-color: #005177;
}
.results-box {
margin-top: 25px;
padding: 20px;
background-color: #f0f8ff;
border: 1px solid #cce5ff;
border-radius: 4px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #daeaff;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
font-weight: 600;
color: #444;
}
.result-value {
font-weight: 700;
color: #0073aa;
font-size: 18px;
}
.seo-content {
line-height: 1.6;
color: #333;
}
.seo-content h2 {
color: #2c3e50;
border-bottom: 2px solid #0073aa;
padding-bottom: 10px;
margin-top: 30px;
}
.seo-content h3 {
color: #444;
margin-top: 25px;
}
.seo-content ul {
padding-left: 20px;
}
.seo-content li {
margin-bottom: 10px;
}
.waste-note {
font-size: 0.9em;
color: #666;
font-style: italic;
margin-top: 10px;
text-align: center;
}
function calculateConcrete() {
// Get input values
var length = document.getElementById('slabLength').value;
var width = document.getElementById('slabWidth').value;
var thickness = document.getElementById('slabThickness').value;
var resultBox = document.getElementById('concreteResult');
// Validate inputs
if (length === "" || width === "" || thickness === "") {
alert("Please fill in all fields (Length, Width, and Thickness).");
return;
}
var numLength = parseFloat(length);
var numWidth = parseFloat(width);
var numThickness = parseFloat(thickness);
if (isNaN(numLength) || isNaN(numWidth) || isNaN(numThickness) || numLength <= 0 || numWidth <= 0 || numThickness <= 0) {
alert("Please enter valid positive numbers.");
return;
}
// Calculation Logic
// 1. Convert thickness from inches to feet
var thicknessInFeet = numThickness / 12;
// 2. Calculate Cubic Feet
var cubicFeet = numLength * numWidth * thicknessInFeet;
// 3. Convert to Cubic Yards (27 cubic feet per yard)
var cubicYards = cubicFeet / 27;
// 4. Add 10% Waste Margin
var totalYardsWithWaste = cubicYards * 1.10;
// 5. Calculate Bags
// Approx 45 bags of 80lb per yard
// Approx 60 bags of 60lb per yard
var bags80 = Math.ceil(totalYardsWithWaste * 45);
var bags60 = Math.ceil(totalYardsWithWaste * 60);
// Display Results
document.getElementById('resYards').innerHTML = totalYardsWithWaste.toFixed(2) + " Cubic Yards";
document.getElementById('res60lb').innerHTML = bags60 + " Bags";
document.getElementById('res80lb').innerHTML = bags80 + " Bags";
// Show result box
resultBox.style.display = "block";
}
Concrete Slab Calculator
Total Volume Required:
0 Cubic Yards
60lb Bags Needed:
0 Bags
80lb Bags Needed:
0 Bags
*Calculations include a standard 10% waste buffer.
How to Calculate Concrete for a Slab
Planning a patio, driveway, or shed foundation requires precise measurements to ensure you order enough material without overspending. This Concrete Slab Calculator helps you determine exactly how many cubic yards of premix concrete or how many bags (60lb or 80lb) you need for your project.
Understanding the Concrete Formula
The math behind calculating concrete volume is straightforward but requires converting all measurements to a standard unit. The formula used is:
Volume (Cubic Feet) = Length (ft) × Width (ft) × (Thickness (in) / 12)
Since concrete is typically sold by the cubic yard, the result is then divided by 27 (since there are 27 cubic feet in one cubic yard).
How Many Bags of Concrete Do I Need?
If you are using pre-mixed bags for smaller projects, the conversion depends on the weight of the bag:
- 80lb Bags: One cubic yard of concrete requires approximately 45 bags (80lbs each).
- 60lb Bags: One cubic yard of concrete requires approximately 60 bags (60lbs each).
Our calculator automatically adds a 10% safety margin (waste factor) to these numbers. This accounts for spillage, uneven subgrades, and variations in slab thickness, ensuring you don't run out of material mid-pour.
Common Concrete Slab Thicknesses
Choosing the right thickness is crucial for the durability of your project:
- 4 Inches: Standard for residential sidewalks, patios, and garage floors (for passenger cars).
- 5-6 Inches: Recommended for driveways that hold heavier vehicles (trucks/SUVs) or heavy equipment.
- 6+ Inches: Heavy-duty industrial floors or foundations requiring high load-bearing capacity.