Every generic concrete calculator I checked before building this one either uses the international 1:2:4 ratio, which isn’t how South African cement, sand and stone are actually specified, or just splits your target volume across the raw ratio numbers, cement, sand and stone by their parts. Both approaches under-order, because loose, dry materials compact once mixed and watered, roughly 1,5 cubic metres of loose cement, sand and stone yields only about 1 cubic metre of set concrete. PPC’s own published guide says as much directly, producing 1 cubic metre of concrete needs 1000 litres of mix, not 1000 litres of raw ratio parts.
This one uses PPC’s own published South African figures for cement bags, sand and stone per cubic metre of finished concrete, by strength grade, a lower-strength mix for foundations, post holes, paths and patios, a medium mix for slabs and driveways, and a high-strength mix for structural or heavy-duty work. It covers slabs, strip footings and fence post holes on the concrete side.
On the mortar side, it works out bricks or blocks per square metre from AfriSam’s published masonry reference, then the cement and sand for a Class II mortar mix, for a single-leaf wall, a double-leaf/cavity wall, or a block wall at three different widths.
Everything comes out in real bags, cement in 50kg bags, sand and stone in 40kg bags, the sizes Chamberlains, Cashbuild and Builders actually sell, with a bulk cubic metre option for bigger jobs and a wheelbarrow figure for mixing on site, not as the buying unit. For concrete it also shows whether bagged pre-mix, mixing your own materials, or getting a ready-mix truck delivered works out cheaper for your exact volume, since that crossover point is easy to get wrong by hand.
Prices default to current South African retail estimates, but every field is editable to your own quote. Let me know if the mix ratios or wastage buffers look off for a job you’ve actually quoted.