Sand and Cement Calculator for Paving Slab

Calculation Formulas:

\[ \text{Cement (kg)} = \left[\text{Area (m²)} \times \text{Thickness (m)} \times 1.33 \times \left(\frac{1}{1 + \text{ratio}}\right)\right] \times 1440 \] \[ \text{Sand (kg)} = \left[\text{Area (m²)} \times \text{Thickness (m)} \times 1.33 \times \left(\frac{\text{ratio}}{1 + \text{ratio}}\right)\right] \times 1600 \]

Cement Required:

Sand Required:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is This Calculator For?

This calculator helps determine the amount of cement and sand needed for paving slab mortar based on the area to be covered, mortar thickness, and your chosen cement:sand ratio.

2. How Does the Calculator Work?

The calculator uses these formulas:

\[ \text{Cement (kg)} = \left[\text{Area} \times \text{Thickness} \times 1.33 \times \left(\frac{1}{1 + \text{ratio}}\right)\right] \times 1440 \] \[ \text{Sand (kg)} = \left[\text{Area} \times \text{Thickness} \times 1.33 \times \left(\frac{\text{ratio}}{1 + \text{ratio}}\right)\right] \times 1600 \]

Where:

Area — Surface area to be paved (m²)
Thickness — Mortar layer thickness (meters)
Ratio — Cement:Sand ratio (e.g., 1:4 = 4)
1.33 — Standard factor for mortar calculations
1440 — Cement density (kg/m³)
1600 — Sand density (kg/m³)

3. Importance of Accurate Calculations

Details: Proper material estimation ensures you have enough supplies without excessive waste, helps with cost planning, and ensures the correct mortar strength for your paving project.

4. Using the Calculator

Tips: Measure your area accurately in square meters. Typical mortar thickness is 25-50mm (0.025-0.05m). Common ratios are 1:3 to 1:5 for paving slabs.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical cement:sand ratio for paving?
A: For paving slabs, 1:4 or 1:5 is common. 1:3 provides stronger mortar but is less workable.

Q2: Why is there a 1.33 factor in the formula?
A: This accounts for the voids in dry sand and ensures proper mortar volume when mixed.

Q3: How do I convert kg to bags of cement?
A: Standard cement bags are 25kg or 50kg. Divide your cement total by the bag size.

Q4: Should I add extra for waste?
A: It's wise to add 5-10% extra to account for spillage and uneven surfaces.

Q5: Can I use this for other mortar applications?
A: While the principle is similar, different applications may require different ratios or additives.