Paver base calculator: crushed base in tons, sand and depth

Enter the area and the compacted depth and you get the crushed base in tons and cubic yards, the bedding sand on top of it, the excavation depth, and the number of truckloads. The number that saves you a second delivery is the compaction factor: crushed base loses 15 to 20 percent of its loose volume under the plate, and this calculator orders for the finished, compacted depth.

How the tonnage is worked out

Base. Area times the compacted depth gives the finished volume in cubic yards. The calculator multiplies that by 1.5 tons per cubic yard, which already includes the 15 to 20 percent lost to compaction. If your yard sells by the loose yard instead of by the ton, order about 1.2 loose yards for every finished yard.

Sand. One inch of coarse concrete sand (ASTM C33), screeded, at about 1.35 tons per cubic yard. Never thicker than an inch; a deep sand bed settles.

Excavation. Base plus sand plus paver thickness. A patio on 4 in of base with a 2 3/8 in paver is dug about 7 3/8 in below finished grade, more where you want a slope for drainage: 1/8 to 1/4 in per foot away from the house.

How deep should the base be?

Compact in lifts of no more than 3 to 4 inches. A single 8 in lift never compacts at the bottom, and that is where driveway ruts start.