How much polymeric sand do I need?
Choose the method that fits your information. A repeated rectangular grid estimates the fraction of the paved area occupied by joints. A measured effective joint length estimates joint strips directly. Product coverage uses the paved area covered by one bag under matching manufacturer conditions.
This paver joint sand calculator does not include the bedding layer beneath the pavers. Polymeric joint products have their own filling and installation requirements. The tool estimates quantities; it does not select a product, joint dimension, activation method or paving design.
Calculate paver joint volume
For a regular grid, let L and W be the paver face dimensions, and g the uniform gap, all in compatible units. Approximate joint fraction = 1 − (L × W) ÷ ((L + g) × (W + g)). Joint area = paved area × joint fraction. Joint volume = joint area × actual sand fill depth.
The paved area includes the pavers and internal gaps. The model is an approximation of repeating cells, not a finite layout or a paver count. It does not resolve edge cuts, spacers, chamfers, mixed sizes, herringbone modules or perimeter joints. For small, irregular or perimeter-heavy areas, use appropriately measured non-overlapping joints or matched product coverage.
For measured joints: volume = effective joint length × uniform joint width × fill depth. Count crossing and branching overlaps only once. Do not blindly add every horizontal and vertical centerline. Calculate different widths or depths separately.
Polymeric sand coverage per bag
Use the manufacturer’s paved-area coverage for the actual product, paver size, gap, fill depth and packing. One bag’s square-foot coverage is not a universal value. If coverage is a range, the calculator shows the whole-bag interval and plans the upper bag count using the lower coverage.
In coverage mode, bags = allowance-adjusted paved area ÷ coverage per bag, rounded up. Joint volume and required weight are not inferred. An optional bag weight shows purchased package weight only. The ordering allowance is separate from the product’s coverage and does not simulate compaction.
INDEPENDENT GEOMETRY EXAMPLE
20 m², 200 × 100 mm paver faces and 5 mm joints
A cell measures 205 × 105 mm. Its joint fraction is (21,525 − 20,000) ÷ 21,525 = 61/861 ≈ 7.085%. With 40 mm of actual fill, the measured joint volume is 48.8/861 m³ ≈ 56.678 L. A separate 10% allowance gives 62.346 L.
With an illustrative applicable density of 1,600 kg/m³, the order quantity is 99.754 kg. Bags of 25 kg require 4 whole bags, about 0.246 kg above that calculated quantity. At an example $35 per bag and one $15 delivery, cost is $155. The dimensions, density and prices are examples, not product specifications or local market rates.
INDEPENDENT COVERAGE EXAMPLE
400 ft² with an illustrative 60–80 ft² per bag
With a 10% allowance, the coverage target is 440 ft². At 80 ft²/bag, ceil(440 ÷ 80) = 6 bags; at 60 ft²/bag, ceil(440 ÷ 60) = 8 bags. The planned quantity is 8, not an average of the range.
If the label says 50 lb, eight bags contain 400 lb purchased. At $35 each plus one $15 delivery: $295. This is an illustrative coverage range, not a preset for any manufacturer. Use the matched rate from your label.
Weight, bags and cost
Geometric or length-mode weight = calculated order volume × the product density applicable to filled joints. Do not substitute solid mineral density or assume a loose density predicts installed packing. If the appropriate density is unknown, the tool leaves required weight unknown. Volume-labelled bag yield can still be used; mass-labelled bags require the density.
Cost = whole planned bags × entered bag price + delivery once. A missing price means cost is unknown; a zero price is allowed. A bag price without bag quantity or yield cannot generate a geometric-mode quote. Changing currency changes the denomination without exchange conversion. Taxes, labor, tools, pavers and installation are excluded.
Sources and assumptions
The Alliance Gator Maxx G2 product page and Supersand Bond page describe coverage as dependent on paver and joint characteristics. These are different products; no shared product coverage or density is assumed here. Check the current instructions for your exact product.
Sakrete’s guidance for existing paving discusses filling depth and preparation. A generic shallow top-up is not an installation recommendation. This calculator does not validate adhesion, drainage, temperature, rain timing or compatibility.
Exact conversions use the NIST reference: 1 ft = 0.3048 m, 1 in = 0.0254 m and 1 lb = 0.45359237 kg. Millimeters are converted exactly as 1 mm = 0.001 m. Internal quantities retain precision; bag counts are rounded up.
Frequently asked questions
How many bags of polymeric sand cover my square feet?
Divide the paved area, including the entered allowance, by the matching manufacturer coverage per bag and round up. If coverage is 60–80 ft²/bag, calculate both limits. Using 60 plans more bags; it is not a guarantee that an unrelated product will achieve that coverage.
Is joint sand the same as paver bedding sand?
No. Bedding sits underneath the pavers; joint sand fills the gaps between them. This page estimates joints. Use the paver base calculator for aggregate base and bedding layers.
Why do joint width and fill depth change the estimate?
Wider gaps occupy more of the paved area and deeper filling increases volume. In the grid model both face dimensions also affect the joint fraction. Enter actual face size rather than a nominal module that already includes the gap.
Can I calculate bags without knowing the sand density?
Yes with a matched area-per-bag coverage or labelled volumetric yield. Geometry plus bags labelled by mass requires an applicable product density. The tool does not assume a universal volume for a 50 lb bag.
Does the geometric model handle mixed-size or irregular paving?
No. It assumes one rectangular face size and uniform gaps in repeating cells. Use matched product coverage, or measured non-overlapping lengths for separately calculated uniform-width sections. The schematic is not a layout or paver count.
Should I subtract existing sand and fill only a thin top layer?
Do not treat this calculator as approval for topping up. Follow the exact product’s preparation and fill-depth instructions. Enter the actual prescribed volume to fill after the required preparation, not an assumed universal shallow layer.
Is the ordering allowance a compaction percentage?
No. It only increases the quantity or covered area by the entered percentage. Manufacturer coverage and an applicable density should already match the intended packing; avoid duplicating allowances included in those figures.
Does the price include installation?
No. It includes only the planned whole bags at the entered price and one delivery. Taxes, labor, paver installation and tools are excluded; no market rates are supplied.