Free Concrete Calculators
FAQs about Calculating the Concrete You Need
Many domestic customers estimate, and that’s common. Suppliers often recommend ordering a small amount extra to avoid running short. Some companies offer part‑load or volumetric options that allow you to adjust the amount on site, reducing waste and extra costs. To work out how much you need use our free concrete calculator.
(From: Free Concrete Calculators)
To calculate a slope, you must find the average depth. Measure the depth at the highest point (D1) and the lowest point (D2), add them together, and divide by two. Use this average depth in your standard volume formula: Length x Width x Average Depth.
(From: Free Concrete Calculators)
The most accurate method is to split the area into simple rectangles. Calculate the volume (Length x Width x Depth) for each rectangle separately and then add the totals together. Be careful not to overlap the measurements at the corner where the two rectangles meet.
(From: Free Concrete Calculators)
The 1.54 conversion factor accounts for the “shrinkage” that occurs when dry ingredients (cement, sand, and stone) are mixed with water. Because dry materials contain air pockets, you need roughly 1.54m³ of dry volume to produce 1.0m³ of wet, compacted concrete. This is vital for DIYers mixing their own materials on-site.
(From: Free Concrete Calculators)
Use the cylinder volume formula: 3.14 x (Radius x Radius) x Depth. For a hole that is 0.3m wide (0.15m radius) and 0.6m deep, the calculation is 3.14 x 0.0225 x 0.6, which equals approximately 0.042m³ per hole. Multiply this by the total number of posts to get your total order volume.
(From: Free Concrete Calculators)
For a domestic driveway carrying standard cars, a minimum depth of 150mm (0.15m) is recommended for structural integrity. For a garden path or patio intended only for foot traffic, a depth of 100mm (0.1m) is usually sufficient.
(From: Free Concrete Calculators)
For a standard C25 (1:2:3) mix, you would need approximately 10 to 12 bags (25kg each) of cement per cubic metre, provided you are mixing with the correct ratio of ballast. If you are mixing individual sand and stone, a C20 (1:2:4) mix typically requires 8 to 10 bags of cement per cubic metre.
(From: Free Concrete Calculators)
Calculate volume by multiplying Length (M) by Width (M) by Depth (M). For example, a 4 metre x 3 metre Patio at 100mm depth (0.1M) is 4 x 3 x 0.1M = 1.2 cubic metres. Always add a 10% contingency for uneven ground or spillage. Or you can use the free concrete calculators on our website.
(From: Free Concrete Calculators)
Calculate Concrete & Order Online
Select the concrete you need from the drop down menu at the top of the calculator
Next enter the measurements for depth, width, and length in whatever measurement formats you have.
If you wish to include the cost of a pump or extra time to barrow off the concrete, then tick the option you require. When you are ready to order click the “Next’ button, and enter your delivery postcode to check if we deliver to that area.
For C10 or C15 Concrete Calculators click here:
C10 Concrete Calculator, C15 Concrete Calculator
How to use our concrete calculator to order
Calculate how much you need, Check the delivery postcode, Order & Pay
Concrete for DIY projects
Concrete Calculators, tips & advice to successfully build these popular home & garden projects.
