Concrete Volume Calculator: Quickly Estimate Your Mix Needs
Whether you’re pouring a new driveway, laying a shed base, or taking on a large commercial slab, getting your concrete quantities right is crucial. In this guide, you’ll learn how to use a concrete volume calculator to work out exactly how much mix you need—saving money, reducing waste, and making your project run smoothly. We’ll walk you through the process, explain common questions, and show a worked example in both metric and imperial units.
Why Use a Concrete Volume Calculator?
Ordering too little concrete means delays, extra delivery charges, and messy patching. Too much, and you’re paying for unused material. A concrete volume calculator takes the guesswork out, giving you an accurate estimate in minutes. It’s ideal for:
- Homeowners planning patios, paths, or shed bases
- Tradespeople quoting for domestic or commercial jobs
- DIYers tackling footings, foundations, or slabs
Ready to get started? Try our concrete volume calculator for free.
How Concrete Volume is Calculated
Concrete volume is generally measured in cubic metres (m³) in the UK and most of the world, or cubic yards (yd³) in the US. To calculate the volume for a rectangular slab:
Volume = Length × Width × Depth
- If your measurements are in metres, your answer will be in cubic metres.
- If you’re using feet, your answer will be in cubic feet—divide by 27 to get cubic yards.
Worked Example (Metric and Imperial)
Suppose you’re laying a patio that’s 4 metres long, 3 metres wide, and 0.15 metres deep (150mm):
| Length | Width | Depth | Volume |
|---|---|---|---|
| 4 m | 3 m | 0.15 m | 1.8 m³ |
Calculation:
4 × 3 × 0.15 = 1.8 m³
For the same patio in imperial units (using feet and inches):
- 4 metres ≈ 13.12 feet
- 3 metres ≈ 9.84 feet
- 0.15 metres ≈ 5.91 inches (0.492 feet)
13.12 × 9.84 × 0.492 ≈ 63.5 cubic feet
63.5 ÷ 27 ≈ 2.35 cubic yards
What About Other Shapes?
Not every job is a simple rectangle. For circular or odd-shaped pours, our concrete volume calculator can handle various shapes—just enter your dimensions and select the shape you need.
Estimating Bags of Concrete Mix
Bagged concrete is common for small jobs. Here’s a quick reference:
| Bag Size | Approx. Volume per Bag |
|---|---|
| 20kg (UK) | ~0.01 m³ |
| 25kg (UK) | ~0.0125 m³ |
| 40lb (US) | ~0.011 yd³ |
| 60lb (US) | ~0.017 yd³ |
| 80lb (US) | ~0.022 yd³ |
So, for our 1.8 m³ example, you’d need around 180 x 20kg bags (1.8 ÷ 0.01), but always check your bag’s packaging for exact yields.
Volumetric Concrete Lorries and Mixers
For larger pours, ready-mixed concrete delivered by volumetric lorry or mixer is best. These vehicles can mix fresh concrete on-site, and you only pay for what you use. Volumetric lorries typically hold between 6 and 10 cubic metres (8–13 cubic yards), but always check with your supplier.
Questions people are actually asking
How much concrete volume per bag?
A standard 20kg bag of ready-mixed concrete yields about 0.01 cubic metres (10 litres) once mixed. For a 25kg bag, it’s roughly 0.0125 m³ (12.5 litres). Always check your product’s packaging for exact coverage.
How much concrete volume?
Concrete volume depends on your project’s dimensions. Use the formula: Length × Width × Depth (in metres or feet), or simply enter your measurements into our concrete volume calculator for a quick answer.
How much is volumetric concrete?
Volumetric concrete is priced per cubic metre (or yard), plus delivery and any extras. Prices vary by region and supplier, but you typically pay a premium for the flexibility of on-site mixing. Contact local suppliers for current rates.
How much does a volumetric concrete mixer hold?
Most volumetric concrete mixers hold between 6 and 10 cubic metres (8–13 cubic yards) of concrete. Some larger trucks can carry even more; always check the specifications before ordering.
How much does concrete weigh by volume?
A cubic metre of typical ready-mix concrete weighs about 2,400kg (2.4 tonnes). A cubic yard weighs roughly 4,000 pounds (1.8 tonnes). The exact weight can vary slightly depending on the mix design and water content.
How much does a volumetric concrete mixer cost?
Buying a new volumetric mixer is a significant investment, ranging from £100,000 to over £200,000 (or equivalent in other currencies), depending on the size and features. Most small contractors choose to hire or order concrete deliveries instead.
How much is a yard of concrete volume?
One cubic yard is approximately 0.7646 cubic metres or 27 cubic feet. If you’re working in metric, 1 cubic metre is about 1.308 cubic yards.
Conclusion
Using a concrete volume calculator is the easiest, most reliable way to get your mix requirements right—no more guesswork, over-ordering, or last-minute dashes to the builder’s merchant. Whether you’re working in metric or imperial, for a DIY project or a large site, our concrete volume calculator will save you time, money, and hassle. Try it now to get your precise mix quantity and make your next pour a smooth success.
Free tools to put this into practice
Reading is one thing — working out your own numbers is what saves time and money. Here are the free HowMuchDoINeed calculators that pair best with this guide:
- Concrete Mix Calculator — work out exactly how much you need and what it will cost.
- Concrete Calculator — work out exactly how much you need and what it will cost.
- Water Volume Calculator — work out exactly how much you need and what it will cost.
- Volume Calculator — work out exactly how much you need and what it will cost.
Explore every free calculator on HowMuchDoINeed — no sign-up required.