Estimate the exact amount of Mapei grout required for your tiling project.
Ultracolor Plus (1.6 kg/dm³)
Keracolor FF / S (1.5 kg/dm³)
Kerapoxy (1.6 kg/dm³)
Kerapoxy Design (1.55 kg/dm³)
Flexcolor (1.7 kg/dm³)
Calculation Summary
*Calculations include a 10% safety margin for waste.
How to Use the Mapei Grout Calculator
Accurately estimating grout is critical for ensuring color consistency across your installation. This calculator uses the official industry formula used by Mapei technical specifications to provide a precise estimate in kilograms.
The Mathematical Formula
The calculation for grout consumption follows the physics of volume displacement. The formula used is:
((A + B) / (A × B)) × C × D × ρ = kg/m²
A: Tile Length (mm)
B: Tile Width (mm)
C: Tile Thickness (mm)
D: Joint Width (mm)
ρ (Rho): Density of the specific Mapei product (kg/dm³)
Mapei Grout Comparison Table
Product
Density
Best For
Ultracolor Plus
1.6
Fast setting, anti-efflorescence
Keracolor FF
1.5
Fine joints, smooth finish
Kerapoxy
1.6
Chemical resistance, hygiene
Pro Tips for Mapei Grout Application
Wait for the Adhesive: Ensure the tile adhesive is fully set (usually 24 hours) before grouting to prevent moisture trapping.
Mixing: Always use the specific water ratio mentioned on the Mapei bag. For Ultracolor Plus, excessive water can cause color pigments to wash out.
Cleaning: Use a damp (not soaking) cellulose sponge to clean joints. Mapei grouts are designed to be high-performance; leaving residue too long can make it difficult to remove.
Waste Factor: Our calculator adds a 10% waste factor. This accounts for grout left in the bucket and residue cleaned off during the sponging process.
Real-World Example
If you are installing a 300mm x 600mm porcelain tile that is 10mm thick, with a 3mm grout joint over 15 square meters using Ultracolor Plus:
function calculateMapeiGrout() {
var A = parseFloat(document.getElementById('tileLength').value);
var B = parseFloat(document.getElementById('tileWidth').value);
var C = parseFloat(document.getElementById('tileThickness').value);
var D = parseFloat(document.getElementById('jointWidth').value);
var area = parseFloat(document.getElementById('totalArea').value);
var density = parseFloat(document.getElementById('groutProduct').value);
var resultBox = document.getElementById('resultContainer');
var kgPerM2Span = document.getElementById('kgPerM2');
var totalKgSpan = document.getElementById('totalKg');
if (isNaN(A) || isNaN(B) || isNaN(C) || isNaN(D) || isNaN(area) || A <= 0 || B <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
// Formula: ((A+B)/(A*B)) * C * D * Density
var consumption = ((A + B) / (A * B)) * C * D * density;
// Add 10% waste factor
var totalNeeded = (consumption * area) * 1.10;
kgPerM2Span.innerHTML = "Base Consumption: " + consumption.toFixed(3) + " kg/m²";
totalKgSpan.innerHTML = totalNeeded.toFixed(2) + " kg Required";
resultBox.style.display = "block";
resultBox.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}