To help you estimate how much gravel you will need to cover the required area, please use our calculator. The calculator is only intended as a rough guide, but will help you approximate the likely volume of gravel or slate needed.

The depth you will need for the aggregate will depend on what size you use and what it is used for. Generally you would lay a 10mm aggregate at 3-4cm (approx 1.5") deep, but on a drive you would go to 5cm (approx 2"). A 20mm aggregate would need to be 4-5cm deep (approx 2") and a little deeper on drives. 

Definitions

• WBS Washed Building Sand: Used for mortar and building.
• White Sand: Used for playpits and white roughcast

• Concrete Sand (Sharp Sand): Used for concrete mix and laying slabs
• Jointing Sand: Used for finishing between monoblocks - 1 bag covers approx 12 sq mtrs