If you want to estimate the required quantity of gravel, chipping, pebbles or cobbles for your driveway, pathway, patio or for your planting area, you should know the dimension of your projects, what is their area and how your depth should be.

Calculating the total amount of gravel, you will need for your pathways can sometimes be overwhelming. So, for help, this article will provide you with easy calculation methods for the amount of gravel you will need for your project. We know what area will a 20kg bag of gravel cover, by knowing this you can make an estimate and how to calculate the amount of gravel you will need for your project.

Landscaping materials such as gravel, chipping, pebbles, or cobbles are used to fill your pathways, driveway, patio, or planting area. As per UK practices, gravel is sold in different bag sizes, small sizes of 25kg bag, 20kg bag, and large sizes of 850kg bag, 900kg bag, which are also known as a Bulk bag or tonne bag.

To calculate the amount of gravel needed to cover your specific area, such as pathways or driveways, you will need to know the length, width, and depth of your space. By calculating the size of your outdoor space, you can easily make a rough estimate

A cubic meter of typical gravel, chipping, pebbles, or cobbles weighs approximately 1,680 kilograms 1.68 tonnes. A square meter of gravel with a depth of 50 mm weighs about 84 kg or 0.084 tonnes. But for estimate purposes, contractors and builders would take 1700kg/m3.

What area will a 20kg bag of gravel cover

If you are looking to fill a driveway or path with gravel, we recommend the depth of the area should be 50mm (5cm) thick as it will experience higher traffic. For covering planted areas, the depth only needs to be around 30mm thick.

As per the general rule of thumb, a 20kg bag of gravel, chipping, or pebbles will cover approximately 0.25 square metres (0.25m2) area at recommended depth of 5cm (50mm) thick, and 0.4 square metres (0.4m2) at 3cm (30mm) thick. So, it would take 4 bags of 20kg gravel to cover 1 square metre area with a depth of 5cm and you will need 2.5 bags of 20kg gravel to cover 1 square metre area with a depth of 3cm. And there are 43 bags of 20kg gravel needed to equate to 1 Bulk bag or tonne bag.

How many a 20kg bag of gravel for 1m2

Generally you will need 4 bags of 20kg gravel, chipping, or pebbles to cover 1 square metre area at 50mm thick, and for 10m2, 40 bags are needed.

How many a 20kg bag of gravel in a bulk bag

Generally there are 43 bags of 20kg gravel in a Bulk or tonne bag. Thus, you will need 43 bags of 20kg gravel to equal 1 Bulk bag or tonne bag.

What area will a 20kg bag of cobbles cover

A 20kg bag of cobbles will cover approximately 0.12 square metres area (0.12m2) at recommended depth of 10cm (100mm) thick. Generally, cobbles are used for pavement roads, streets, and buildings.

How much does a 20kg bag of gravel cover

As per UK practices, a 20kg bag of gravel, chipping, or pebbles can cover approximately 0.25 square metres (0.25m2) area at recommended depth of 5cm (50mm) thick, and 0.4 square metres (0.4m2) at 3cm (30mm) thick.

How to calculate the amount of gravel I need

The amount of gravel you will need depends on the square footage and depth of your projects in cubic metres or cubic feet.

The first step is to calculate the area of the section you would like to cover with gravel. The area calculation = length x width (where length & width are 2 sides of a square or rectangular area).

The second step is to calculate the volume of the section you would like to cover with gravel. The volume calculation = square footage × depth, result gives us, the amount of gravel required for projects

Suppose, if you are creating a patio of 5m long by 4m wide at 5cm thick, the first step is to calculate area = 5m × 4m = 20m2, then the second step is to calculate volume = 20m2 × 0.05m = 1m3, this is required quantity of gravel, so, you will need 86 bags of 20kg gravel or 2 bulk bag to cover 20 square metres area at a standard depth of 5cm thick.

Conclusions: -

As per general rule of thumb, a 20kg bag of gravel, chipping, or pebbles will cover approximately 0.25 square metres (0.25m2) area at recommended depth of 5cm (50mm) thick, and 0.4 square metres (0.5m2) at 3cm (30mm) thick.