How much concrete do I need?

[ottosump]

Hi group, can anyone tell me approximately how much concrete I should order for the planned driveway pictures, please ignore the 2.5m section detailed on the right, that has now been taken out.
Thank you..

 

[matlob]

Depends how deep but looks to be about 2 cubic meters

 

[noseall]

1.5 cube at 100mm thick.

 

[ottosump]

1.5 cube at 100mm thick.

Really, is that all, I thought it was going to be about 2.5m at 4 inch

 

[matlob]

Sounds right I calculated based on 150mm

 

[ottosump]

Thanks guys, I worked the area out at approx 13.4 square metres

 

[noseall]

Really, is that all, I thought it was going to be about 2.5m at 4 inch

It's only 1.8 cube if you square off the rectangle i.e. 5.12m x 3.64m x 0.1. Then you have to remove the triangle which brings it down to 1.5 cube.

 

[cdbe]

Don't "order" an amount, use a barrow mix company and try to find one with a low minimum order amount. 1.5m is barely worth them starting up the lorry for but at least you'll only pay for exactly what you need.

 

[ottosump]

Ordered 1.5m, used approx 1.2m on the drive, we did bulk it out with old bricks and re-bar though, used what was left over on my own property, luckily I,d shuttered an area of anticipating ordering too much so none wasted. Was £216 delivered and the crete had fibres in it, never used that before.
Thanks everyone for the advice, much appreciated.

 

[MaxBuilds]

The maths are straightforward — it's length x width x depth, all in metres, which gives you cubic metres directly. For the original poster's drive, 13.4 m² at 100 mm (0.1 m) thick is 13.4 x 0.1 = 1.34 m³, and once you add a sensible 10% allowance for uneven sub-base and spillage you're at roughly 1.5 m³, which lines up with what everyone said above.

As a rule of thumb for anyone working it out: measure the area in square metres, multiply by the thickness in metres (100 mm = 0.1 m, 150 mm = 0.15 m), then add 10% on top. If you're unsure about the thickness, go a touch deeper — a thin slab cracks, a slightly thick one just costs a little more.

If you want to double-check your own numbers before ordering, this free calculator does the whole thing for you: https://concretecalcus.com