If you are planning on using gravel, chippings or any other decorative aggregate to complete a project then it’s important to understand how much you will need. If you underestimate how much you need you could end up paying for additional deliveries which costs time and money. On the other hand, buying too much creates a lot of unnecessary waste.

How Do I Calculate How Much Gravel I Need?

You must measure the size of the area you intend to cover in order to determine the quantity of aggregate you require. You will also need to take into consideration the depth required.  

Most 10mm aggregates will need to be laid at a depth of 30-40mm, but if used to create a driveway this would need to be at least 50mm. A 20mm aggregate would need to be at a depth of at least 40-50mm and at least 50-60mm on driveways.  It’s worth noting that a larger aggregate will settle and bond together better than smaller ones.

The following table can be used as a guide to help you work out a rough estimate, but remember it’s always better to buy too much than too little.

Coverage Area30mm Depth40mm Depth50mm Depth
1m21 bulk bag - approx 0.06 tonnes1 bulk bag - approx 0.08 tonnes1 bulk bag - approx 0.10 tonnes
5m22 Bulk Bags - approx. 1.5 tonnes3 Bulk Bags - approx. 2.0 tonnes3 Bulk Bags - approx. 2.50 tonnes
10m28 Bulk Bags - approx. 6.0 tonnes10 Bulk Bags - approx. 8.0 tonnes12 Bulk Bags - approx 10.0 tonnes
25m245 Bulk Bags - approx. 37.50 tonnes59 Bulk Bags - approx. 50.00 tonnes74 Bulk Bags - approx. 62.50 tonnes

Driveways & Gardens

For driveways you will need to know the desired length and width plus the recommended depth as stated above depending on the gravel you use.

For gardens, this can be a little trickier because shapes may not be perfectly square. We would suggest extending your measurements to make it square so that you do not run out of materials.

Calculating For Pots & Beds

You can use the above table to help you calculate your gravel requirements for pots and beds.  We would recommend using a depth of 40mm for flowerbeds.  It’s best to calculate the required amount for individual areas and then add together if you are planning on using chippings or gravel for multiple beds. 

Can I Use this To Calculate For Building Aggregates?

Yes however, it may not provide you with perfect accuracy due to the various densities of these materials.  It will certainly provide a rough guide for aggregates such as sub base and sand
You can browse our full range of aggregates, gravels and decorative chippings here.  These are available to buy in a choice of bag sizes including bulk bags and small builders bags.  These are suitable for a wide range of landscaping and building projects.  If you would like some help calculating how much gravel you will need or just require further information about any of our products, please do get in touch: 01752 393939 or SALES@KPTTIMBER.CO.UK.