How much stones/shingle to buy to fill sleepers?

Using sleepers to add different levels to your garden is a popular DIY project. But you’ll need to fill your sleepers with some kind of infill material – often stones or shingles, as they’re good for drainage.

Planning on using sleepers in your garden to build a retaining wall, planting bed, garden seat or even steps?

Using sleepers to add different levels to your garden is a popular DIY project. But you’ll need to fill your sleepers with some kind of infill material – often stones or shingles, as they’re good for drainage.

So, there’s one big question you probably have on your mind, especially if you’re new to this kind of project: how much stones or shingles should you buy to fill the sleepers?

Here, we’ll show you how to calculate it.

Calculating how much stones/shingle to buy to fill sleepers

1. Calculate the size of the area you need to fill

To work out how many stones/shingles you need, you’ll first need to calculate the size of the area you need to fill.

To do this, measure the length, width and depth (in metres). Then multiply them together. This will tell you the size of the area in cubic metres (m³).

2. Check the weight of your stones/shingles per m³

To make matters a little more complicated, shingles and gravel are usually sold by weight.

As a rough rule of thumb, here’s how much you’ll need to fill one m³.

• Shingles: 1.62 tonnes per m³

• Gravel: 1.92 tonnes per m³

Of course, this will vary a bit depending on the size and material of the aggregates you’re using, but this is a good place to start.

3. Work out how much weight you need

Next, you’ll need to work out how many tonnes you need to fill the area you’ve calculated.

To do this, multiply the weight of your chosen material per m³ by the m³ of the area you need to fill. In other words, multiply the number you got to in step 1 by the number you got to in step 2!

We’d recommend rounding up your calculations as it’s always useful to have some spare – and it’s not an exact art!

4. Calculate how many bags you need

Finally, you’ll have to decide how many bags of stones/shingles to buy.

To work this out, divide the total number of tonnes you need by how many tonnes you get in a bag and voila! That’s how many bags you’ll need.

For example, if you want 6 tonnes of gravel in total and your chosen material is sold in 1-tonne bags, you’ll need 6 bags of gravel (6 ÷ 1 = 6). Simple!

Get the help of a professional

If you want to nail your project, why not enlist the help of an expert?

A professional landscaper will be able to help you calculate exactly how many stones or shingles you need to fill your sleepers. Plus, they’ll even be able to do all the heavy lifting for you, so that you don’t have to break a sweat (and they’ll make sure your job is completed to a high standard that you can be proud of).

Read our guide to garden landscaping costs to learn more.

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