How Much Concrete Do I Need? Concrete Calculator for Any Project

Whether you’ve had experience laying concrete before or this is your first concreting project, we have detailed how much concrete you will need for your desired project. The three primary considerations to factor in are:

  • The area you’re concreting
  • Your budget
  • The type of concrete you want to use

You do not have to have the years’ of experience to effectively lay and install concrete on a small scale, by following our simple instructions and referring to our concrete calculator, we can help you install and transform your indoor or outdoor property.

How to Calculate How Much Concrete You Need

This can be performed in simple steps:

  • Consider how thick you’d like your concrete to be
  • Take measurements of the area you’re concreting (whether it’s your garden shed or patio, driveway, kitchen etc)
  • Next, you need to determine square footage – do this by multiplying the length by the width
  • Convert the thickness from inches to feet
  • Then, multiply the thickness (in feet) by the square footage to determine cubic feet
  • Next, you need to convert cubic feet into yards – do this by multiplying it by 0.37

Putting it into practice

Let’s say you’re undertaking a garden patio project and the patio measures 10ft by 10ft, here’s how the process would look:

10 x 10 = 100 square feet
4 ÷ 12 = 0.33
100 x .33 = 33 cubic feet
33 x .037 = 1.22 cubic yards

This formula helps you find the volume and then convert it to cubic yards. If you require the concrete formula, it is simply:

Length X Width X Thickness

How many bags of concrete do you need?

For bags, you will need to divide the total cubic yards by the yield. The yield is the volume of fresh concrete produced in a batch, expressed in cubic meters. It is calculated by dividing the total mass of the material by the measured density of the freshly mixed concrete. This will help you find out the amount of concrete your project requires.

Below, we have explained the yields and bag sizes required:

For example: if you have 10 circular holes with a diameter of 300 mm and filled to a depth of 600 mm with a total volume of 0.424 m³ – you will need roughly 45.8 x 20 kg bags of concrete.

Alternatively, you can look at it this way:

  • 40 pound bag yields .011 cubic yards
  • 60 pound bag yields .017 cubic yards
  • 80 pound bag yields .022 cubic yards

Should I order concrete by the yard from a ready mix company or just use bags?

If you are attempting to concrete a larger domestic area, such as a driveway or a large garden, you will find it more beneficial and cost-effective to order concrete by the yard. Otherwise, you will end up with a very labour-intensive job mixing bag after bag by hand.

If you are completing a smaller job, such as a kitchen, conservatory or small outside space, then you should consider calculating concrete by the bag.

Put simply, bagged concrete is ideal for:

  • Smaller jobs, such as pouring slabs to erect pavements, patios or indoor hallways/kitchens
  • Setting posts for fences and fence panels along your garden path
  • Minor repairs to walls, steps, patios and driveways
  • Creating small ramps and speed bumps
  • Foundations (footings) and post holes for small porches, pergolas and similar outdoor structures

For customers looking to buy bagged concrete, most companies will deliver to your doorstep. However, there is a limit to how many bags of concrete you can order with the majority of companies. If you are undertaking a large scale project, you may have to pick up and transport the concrete yourself.

Additional equipment to mix the concrete

Unless you already own or have access to a concrete mixer, you will need to hire or purchase one. Smaller concrete projects can get away with using a wheelbarrow to mix the concrete, but larger projects will require a mixer.

Ready mixed concrete by the yard is good for:

  • Driveways, large garden patios, sport courts and small car parking spaces
  • Foundation slabs for a house
  • Parking lots or commercial sidewalks

If you do go down the path of ordering your concrete from a concrete mix supplier, you will need to provide them with how much concrete you need (in yards). Most mixing companies will state that your order must be over one yard, if not, they may charge you extra due to the small amount being ordered. The concrete is typically delivered in a truck or multiple tracks for bigger orders.

Undertaking a large concrete project? Contact the experts

If your concrete project is on a larger scale and you would rather employ a team of experienced contractors to undertake the task, we can provide this service. At Concrete Flooring Solutions, we have over 40 years’ experience in the concrete industry and have installed concrete flooring across the UK. From multi-storey car parks and warehouses to huge retail stores and city pavements, we have the experience and technology to provide lifelong concrete flooring for all properties and outdoor areas.

Choose from polished concrete for a stunning, life-long finish for large indoor areas, industrial concrete, for car parks and other heavy traffic areas to composite metal decking to lay the foundations of your concrete.

When you’re ready to contact us, simply enter your details and enquiry on our contact form, or call us using the number above.