Polymeric Sand Calculator

To find the polymeric sand needed, multiply length by width for each paved area and add them. Divide the total by the coverage printed on the bag, scaled for your joint width. Multiply by one plus the waste percent and round up to a whole bag.

Steps

1. Measure each paved area in feet and multiply length by width. Add the areas.
2. Read the bag. Note the coverage in square feet and the joint width it quotes.
3. Measure your paver length and width and choose your joint width.
4. Let the calculator scale the coverage to your joints.
5. Add waste and round up to a whole bag.

Bags = ceiling( area x (1 + waste / 100) / coverage )
Coverage = bag coverage x joint share on the bag / your joint share

The first line is the usual rule: area divided by coverage. If you need the area first, the square footage calculator finds it. The base layers under the pavers are covered by the paver calculator.

The count depends on area, joint width and the bag. The table uses 4 by 8 inch pavers, 3/16 inch joints, a bag rated 40 square feet at 1/4 inch joints, and 10 percent waste. A 192 square foot patio needs 5 bags.

The 12 by 16 foot patio is 192 square feet. The bag covers 52.42 square feet at 3/16 inch joints, so 192 times 1.10 divided by 52.42 is 4.03 bags. That rounds up to 5. The raw figure sits just above 4, so a small change in joint width or waste moves the count.

Read the table down the area column. Each row uses the same pavers, joints, bag and waste as the example, so only the area changes. The 12 by 12 foot patio comes to 3.02 bags before rounding, which is 4 to order. Larger patios scale in a straight line with area, then round up once at the end, not once per area.

A wider joint holds more sand, so a bag covers less. Inch Calculator lists 30 to 60 square feet per 50 pound bag for gaps of 1/4 to 3/8 inch. Our paver page uses 50, 40 and 25 square feet for 3/16, 1/4 and 3/8 inch joints.

The calculator scales the 40 square foot rating by the ratio of joint shares. At 3/16 inch it gives 52.42 and at 3/8 inch it gives 27.59 square feet, close to the 50 and 25 on our paver page. Paver thickness also matters. Inch Calculator notes that a 3 inch brick paver needs more sand than a 1 inch flagstone paver.

Joint share is the part of the surface taken by joints: one minus paver length times width, divided by the length plus joint times the width plus joint. Multiply the area by joint share and fill depth to get the volume of sand in cubic feet.

Fill depth is the paver thickness less the gap below the top. We use 1/8 inch as a default assumption and you can change it. Smaller pavers have more joint per square foot, so they hold more sand. Paver counts and base layers are on the paver calculator. Bedding sand is on the sand calculator.

Flagstone with large, irregular gaps needs far more sand. Inch Calculator gives about 8 to 10 square feet per 50 pound bag for that case, against 30 to 60 for 1/4 to 3/8 inch joints. This calculator models even joints between regular pavers only.

For flagstone, use the coverage on the bag as your guide and ask your supplier. Joint scaling assumes a regular grid, which irregular stone does not have. For stone and brick quantities, see the brick calculator.

Polymeric sand holds a binding agent that sets when misted. It locks the pavers and blocks weeds. Regular sand has no binder. This page counts bags of polymeric sand only and does not compare brands, products or climate fit.

Our paver page notes that makers advise dry-sweeping the sand into the joints, blowing off the excess and misting, not soaking. Follow the instructions on your bag. For the gravel base under the pavers, use the gravel calculator. For tile jobs, see the tile calculator.

We default to 10 percent for sweeping loss and spills. That is our assumption, not a sourced rule, so change it. Our paver page also advises one spare bag. The table shows how the count moves for the 192 square foot example.

This page has no sourced waste figure for complex patterns or curved edges, so ask your supplier. In this example, 0 and 5 percent both give 4 bags, and 10 and 15 percent both give 5. The step happens where the raw count crosses 4.

Published October 2026. Last updated October 2026. Next review October 2027.

Marcus Johnson, CCMCCM

Reviews: project calculators · 31 calculators reviewed

Marcus Johnson is a Certified Construction Manager (CCM) with 20 years of experience in residential and commercial site work. He holds CCM certification from CMAA (member #2019-1247). He has managed NALP-member landscape installation projects covering more than 2 million square feet of site work. At CalcSummit, he writes all landscape volume and bulk-material calculators, applying field-tested coverage rates for mulch, gravel, sand, topsoil, and fill dirt.

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