Paver Sand Calculator

How this is calculated

⚠️ THE BEDDING SAND LAYER IS 1 INCH. Not two, not three, and not 'however much it takes to level it out'. This is the rule that separates a patio that stays flat from one that ruts and dips within a season, and it is the commonest mistake in the whole job. WHY THICKER IS WORSE, WHICH IS GENUINELY COUNTERINTUITIVE: bedding sand is a setting layer, not a levelling layer. Its job is to let each paver seat itself evenly onto a base that is ALREADY flat. Sand cannot be compacted into a stable structure the way graded aggregate can - so the more of it you have, the more there is to migrate sideways under load. A 3 inch sand bed will move under a wheelbarrow, under furniture legs and under anyone who stands in the same spot often. Every dip you have seen in a paved patio is that. SO IF THE SURFACE IS UNEVEN, FIX THE BASE. The levelling happens in the compacted aggregate underneath, screeded and plate-compacted flat. Using extra sand to hide a bad base does not fix the base, it just delays the evidence by a few months. THE ARITHMETIC IS CLEAN: a cubic yard is 27 cubic feet, and at 1 inch deep - one twelfth of a foot - it covers exactly 324 square feet. That is a genuinely exact number, not a rounded one, and it is worth remembering: 324 square feet per yard per inch. DENSITY VARIES AND IS THEREFORE AN INPUT. Concrete or masonry sand runs roughly 2,600 to 2,900 pounds per cubic yard depending on how damp it is - and sand sold by weight is almost never bone dry, which is why a supplier's tonnage and your volume calculation will rarely agree exactly. Order by VOLUME where you can. If you must order by weight, ask the supplier what their material actually weighs rather than assuming. USE THE RIGHT SAND. Coarse, sharp, angular concrete or masonry sand is what goes under pavers - the angular grains lock against each other. Fine, rounded play sand or builder's soft sand does not lock, holds water and will not hold a paver still. This is not interchangeable and the bags do not always make the difference obvious. JOINT SAND IS A COMPLETELY DIFFERENT PRODUCT and this calculator does not cover it. The sand swept into the gaps between pavers when the job is done is fine-graded or polymeric, and the amount depends on your joint width and paver size rather than on the patio area. Buy it separately and do not use the bedding sand for it. SCREED, DO NOT WALK. Once the sand is screeded flat, nobody stands on it - a footprint is a dip, and a dip that gets a paver laid over it stays for the life of the patio.

Common questions

How much sand do I need for a paver patio?

For a 20 by 12 foot patio - 240 square feet - at the correct 1 inch bedding depth: 0.74 cubic yards, which is about 1 ton, or 20 cubic feet if you are buying it bagged. The useful shortcut to remember is that one cubic yard covers exactly 324 square feet at one inch, because 27 cubic feet divided by one twelfth of a foot is exactly 324.

How thick should the sand layer be?

One inch. Not two, not three, and not however much it takes to make the surface look level. This is the single rule that decides whether a patio stays flat, and getting it wrong is the commonest mistake in the job. The calculator deliberately shows how much extra sand you are adding above one inch, and the right answer for that figure is zero.

Why is a thicker sand bed worse?

Because bedding sand is a setting layer, not a levelling layer, and this is genuinely counterintuitive - more of it feels like more cushioning and better levelling. Sand cannot be compacted into a stable structure the way graded aggregate can, so the more of it there is, the more there is to migrate sideways under load. A 3 inch bed will move under a wheelbarrow, under furniture legs and under anybody who stands in the same spot regularly. Every dip you have seen in a paved patio started like that.

My base is uneven — can't I just use more sand?

You can, and it will look perfect for a few months. The levelling belongs in the compacted aggregate base underneath, screeded and plate-compacted flat before any sand goes down. Using sand to hide a bad base does not fix the base; it delays the evidence until the first winter, at which point the fix involves lifting the pavers you just laid. If the base is not flat, the honest move is to go back to it.

What kind of sand?

Coarse, sharp, angular concrete or masonry sand. The angularity is the whole point - the grains lock against each other and hold a paver still. Fine rounded play sand and soft builder's sand do not lock, hold water, and will let pavers wander. These are not interchangeable products and the bags do not always make the difference obvious, so read past the word 'sand' on the label to what the grade actually is.

Should I order by weight or by volume?

By volume where you can. Sand sold by weight is almost never bone dry, and moisture content is exactly what varies - concrete sand runs roughly 2,600 to 2,900 pounds per cubic yard depending on how wet it is, which is a spread of more than 10%. That is why your calculation and a supplier's tonnage will rarely agree precisely. If you have to order by weight, ask the supplier what their material actually weighs rather than using a figure off the internet, including this one.

What about the sand between the pavers?

Different product, different calculation, and this tool does not cover it. Joint sand - the fine-graded or polymeric sand swept into the gaps once the pavers are down - depends on your joint width and paver size rather than on the patio area, so it does not scale the same way. Buy it separately, and do not be tempted to use the coarse bedding sand for it: the grains are too large to fill the joints properly and it will keep washing out.

Any advice for laying the bed?

Screed it, then do not walk on it. Once the sand is screeded flat, a single footprint is a dip, and a dip with a paver laid over it stays for the life of the patio. Work from the pavers you have already laid rather than stepping onto the bed, screed only as far ahead as you can reach, and resist the urge to tamp the sand down - it is compacted by the plate compactor at the END, through the pavers, not before they go on.

Take it further with AI

Copy this into ChatGPT or Claude with your own numbers filled in. It hands over the figures this calculator worked out, so the answer is built on real arithmetic instead of a guess.

I used the Paver Sand Calculator at https://www.bfcbrilliance.com/tools/paver-sand-calculator.

What I entered:
- Patio length (ft): ___
- Patio width (ft): ___
- Bedding depth (in): ___
- Sand density (lb/cu yd): ___
- Bag size (cu ft): ___

What it calculated:
- Sand needed: ___
- In cubic feet: ___
- In tons: ___
- Bags: ___
- Patio area: ___

Use those figures as given — they are already worked out, so please don't recalculate or estimate your own. Help me turn them into a plan: what to buy or do, in what order, roughly what it should cost, and the mistakes people most often make with this job.

Where the job touches structure, gas, or electrics, tell me to check local building code and whether a permit or a licensed trade is required.

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