Polymeric sand calculator: bags by area and joint width
Enter the area and the joint width and you get the number of 50 lb bags of polymeric sand to buy, with a line for your price per bag. Joint width is what moves the number: a tight-jointed concrete paver patio takes less than half the sand of a tumbled or natural stone job of the same size.
How the bag count is worked out
A 50 lb bag covers about 80 sq ft with tight 1/8 in joints, 50 sq ft with 1/4 in joints, 30 sq ft with 3/8 in joints, and about 20 sq ft on flagstone with joints up to an inch. The calculator divides your area by that coverage, scales for the bag size you buy, and adds the spare percentage you choose. Round up to whole bags: running out two joints from the end is how a job gets a second visit.
Manufacturers publish their own coverage charts and they differ by a few square feet per bag. If the bag you buy says otherwise, trust the bag.
Getting it right on the day
| Step | What matters |
|---|---|
| Dry pavers | Surface and joints bone dry, or the polymer sets on the face and hazes. |
| Sweep and compact | Sweep in, run the plate compactor with a pad, sweep again, repeat until the joints stop taking sand. |
| Blow off | Leaf blower at low speed, held high, until no sand sits on the faces. This is where haze is prevented. |
| Water | Shower setting, small sections, until water stops soaking in. No puddles, no washout. |
| Weather | No rain for 24 hours, above 32°F overnight. |
JobsBooks prices the whole paver job, gets the proposal signed online, and tracks what it actually costs against the quote. Free for one company.
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