How Much Concrete Do You Need for a Shed Base?
- Admin
- Feb 2
- 4 min read
If you're planning to install a shed in your garden, one of the most important steps is creating a solid base. A concrete shed base is one of the most durable and reliable foundations you can use, helping to keep your shed level, dry and stable for years to come.
One of the most common questions homeowners ask is:
How much concrete do I actually need for a shed base?
Whether you're installing a shed in Bexhill, Hastings, Battle, Robertsbridge, Rye, Tenterden, Tonbridge or Paddock Wood, calculating the right amount of concrete is essential before ordering materials or arranging delivery.
In this guide, we’ll explain how to calculate the amount of concrete needed for a shed base, recommended thickness, and the easiest way to work it out using our online calculator.
Recommended Concrete Thickness for a Shed Base
For most garden sheds, the recommended thickness of a concrete base is:
100mm to 150mm (4–6 inches)
However, thicker concrete may be needed if:
The shed is particularly large
The building will store heavy equipment
The ground conditions are poor
Vehicles or machinery may be placed onto the base
If you're unsure, it's always better to slightly overestimate rather than pour a base thats' too thin.
How to Calculate Concrete for a Shed Base
Concrete is usually ordered in cubic metres (m³) in the UK.
To calculate the amount needed, you use a simple formula:
Length × Width × Depth = Volume of concrete
All measurements must be in metres.
Example calculation
If your shed base is:
3 metres long
3 metres wide
100m deep (0.1m)
The calculation would be:
3 x 3 x 0.1 = 0.9 cubic metres
So you would need approximately 0.9m3 of concrete.
In most cases it’s advisable to order slightly more than the exact amount to allow for small variations in ground level and preparation.
Common Shed Base Sizes and Concrete Volumes
Many sheds are sold in standard sizes. Below are rough estimates for typical shed bases at 100mm thickness.
Shed Size | Approx Concrete Required |
6ft x 4ft shed | 0.45 m3 |
8ft x 6ft shed | 0.75 m3 |
10ft x 8ft shed | 1.2 m3 |
12ft x 8ft shed | 1.45 m3 |
These are estimates only, as ground preparation and exact depth can vary.
Use Our Concrete Calculator (Metric or Imperial)
While it’s possible to calculate concrete volumes manually, the easiest way is to use our online concrete calculator.
At William the Concreter, our calculator allows you to work out how much concrete you need using either:
metric measurements (metres and millimetres)
imperial measurements (feet and inches)
This is especially helpful because many shed sizes are still sold in imperial dimensions, such as 6×4 ft, 8×6 ft or 10×8 ft, while concrete is normally ordered in cubic metres.
Our calculator automatically converts imperial measurements into metric and estimates the volume of concrete required.
This makes it quick and easy to estimate how much concrete you need before ordering.
Preparing the Ground for a Shed Base
Calculating the amount of concrete is only part of the process. Proper ground preparation is essential to ensure your shed base lasts.
Typical preparation steps include:
Marking the area: Mark the exact footprint of the shed base using stakes and string.
Excavating the ground: Remove soil to the required depth, allowing space for the sub-base and concrete.
installing the sub-base: A compacted layer of MOT Type 1 hardcore helps create a stable foundation
Installing formwork: Timber boards are placed around the edges to contain the concrete while it sets.
Pouring and levelling concrete: The concrete is poured into the formwork and levelled to create a smooth, flat surface.
Common Mistakes When Pouring Shed Bases
Many DIY shed bases fail because of small mistakes. Some common problems include:
Base too thin: Concrete that is too thin can crack under weight.
Poor ground preparation: Skipping the sub-base layer can cause sinking or movement over time.
Ordering too little concrete: Running out of concrete mid-pour can cause weak joins.
Uneven surfaces: Improper levelling can leave the shed leaning or unstable.
Using the correct volume of concrete and preparing the base properly helps avoid these issues.
Concrete Delivery for Shed Bases in East Sussex and South Kent
If you're building a shed base and need concrete delivered, we supply volumetric concrete across East Sussex and South Kent.
We regularly deliver concrete for shed bases in:
Bexhill
Hastings
Battle
Robertsbridge
Rye
Tenterden
Cranbrook
Paddock Wood
Volumetric concrete allows us to mix the exact amount needed on site, helping to reduce waste and ensure you get the right quantity for your project.
Need Help Calculating Concrete?
If you're unsure how much concrete your shed base requires, the quickest way to find out is by using our our calculator.
Alternatively, you can contact William The Concreter for advice on concrete delivery and shed base projects across East Sussex and South Kent.