🧱Paving calculator

Running short of pavers halfway through a job is one of the most expensive mistakes in landscaping, because the next batch rarely matches the colour of the first. Over-ordering ties up money and leaves you with a stack of bricks in the corner of the garden. This calculator gets the number right up front, using the one thing most people leave out of the sum: the actual size of the paver.

How the paving calculator works

It is simpler than it looks. The tool takes the area you want to pave, either directly or from a length and width, and divides it by the footprint of a single paver. A standard brick paver of 220 by 110 mm covers 0.0242 square metres, which works out to roughly 41 pavers per square metre. A 400 by 400 mm slab covers 0.16 square metres, so you need only about 6 per square metre for the same space. That is why ordering by a rough brick count, without pinning down the size, goes wrong so often.

The calculator then adds a wastage percentage for cuts and breakages, and rounds up to whole pavers. It also estimates the bedding sand you need underneath, at a standard 50 mm depth.

Why pavers per square metre is the number that matters

Suppliers quote and price paving by the square metre, but they deliver a count of pavers. The bridge between the two is the pavers-per-square-metre figure, and it swings enormously with size. Get that figure wrong and every downstream number is wrong: the order, the price and the delivery. Working from area and paver size, rather than a guessed total, is the difference between one clean delivery and a frustrating top-up run. For the count of every common size, see our guide to how many pavers per square metre.

How to measure your area

• ✓Measure length and width in metres and multiply them. For a 5 by 4 metre patio that is 20 square metres.
• ✓Break odd shapes into rectangles, work out each one, and add them together.
• ✓For a circle, multiply the radius by itself and then by 3.14.
• ✓Measure at the widest points and round up, never down.
• ✓Laying in a pattern like herringbone or at 45 degrees means more cuts, so push your wastage higher.

Wastage is not optional

For a simple rectangle with straight edges, 5 percent covers the odd breakage. For curves, circles, diagonal patterns and anything with lots of cutting, allow 10 percent or more. There is a second reason to over-order slightly: keep a small stack of spares from the same batch. Paving colours shift between production runs, so a repair done two years later with fresh stock will always stand out. Spares from the original batch will not.

Do not forget what goes under the pavers

The single most common paving failure we are called to fix is not the pavers, it is the base. Pavers sit on a bed of sand, which this calculator sizes for you at 50 mm. Under that, a patio wants a firm, compacted layer, and a driveway that carries a car needs a proper compacted sub-base or it will sink and rut within a season. You also need jointing sand brushed into the gaps, and an edge restraint around the perimeter so the whole field does not slowly spread and open up. Skimping on the base saves a little now and costs a full relay later.

Common mistakes when ordering paving

• ✓Ordering by brick count without fixing the paver size first.
• ✓Allowing no wastage, then running short on the last square metre.
• ✓Budgeting for pavers but forgetting bedding sand, jointing sand and edge restraints.
• ✓Mixing batches, so repairs and top-ups show as a different shade.
• ✓Ignoring the fall, so water pools on the patio instead of draining away.
• ✓Under-building the base on a driveway, which leads to sinking and cracking.

Once you have your quantities, the harder part is the base preparation, levels and drainage. That is where we come in: our team lays paving as part of hard landscaping across Paarl and the Winelands. For where paving fits into a wider design, see our landscaping ideas guide.