How to Measure and Order for Your Project

Accurately estimating the quantity of cobblestone needed is crucial to avoid costly overages or frustrating shortages. Unlike uniform pavers, cobblestone requires a different calculation approach due to its irregular shape and jointing.

The 3-Step Estimation Method:
Step 1: Calculate the Area (Square Meters/Feet)

For rectangles: Length x Width.

For circles: π (3.14) x (Radius x Radius).

Pro Tip: Draw your project area to scale and divide it into simple shapes. Calculate the area of each, then add them together.

Step 2: Determine Cobble Coverage Factor
This is the key variable. Because of irregular shapes and joints, a square meter of cobblestones uses less stone and more joint space than a square meter of solid slab.

Standard Dry-Laid Cobbles (with sand joints): ~55-65 stones per square meter for 100-150mm cobbles. This covers approximately 70-80% of the area, with 20-30% being joint space.

Tightly Mortared Cobbles: May use slightly more stones per m² as joints are thinner.

Step 3: Calculate Quantity & Add Waste Factor

Formula: (Total Area in m²) x (Stones per m²) = Total Stones Needed (Base Quantity)

Waste Factor: MUST be added for cuts, breakage, and future repairs.

Simple rectangular area: Add 10%

Complex shape with many cuts (circles, curves): Add 15-20%

Final Order Quantity = Base Quantity x (1 + Waste Factor)

Example Calculation:
A 50m² patio using standard cobbles (60 stones/m²) with a complex shape (15% waste).

Base Quantity: 50 m² x 60 = 3,000 stones

Waste: 3,000 x 0.15 = 450 stones

Final Order: 3,450 stones

Don't Forget Ancillary Materials:

Bedding Sand (for dry-laid): ~50kg per m²

Jointing Sand: ~15kg per m²

Edge Restraints: Linear meters of concrete curb or metal edging.