The paver sandwich, from the dirt up
Every paver surface that survives freeze and rain is the same sandwich: compacted subgrade soil, geotextile fabric on soft soils, 4 to 8 inches of compacted crusher run base, exactly 1 inch of screeded concrete sand, then the pavers with sand swept joints. The base carries the load; the sand is only a leveling course. This calculator sizes the two bought layers and tells you the excavation depth so your finished patio lands flush with the lawn instead of proud of it.
Base depth by traffic
Foot traffic (patios, walkways): 4 inches of compacted base. Vehicles (driveways): 6 inches minimum. Clay or soft soils: add 2 inches over the standard and put non woven fabric under the base to stop the stone from punching into the subgrade. These are the industry standard ICPI figures, and the difference between a patio quote and a driveway quote is mostly this base tonnage; a 16 x 12 patio needs about 2.9 tons of base, while the same area built for cars needs 4.4.
Compact in lifts, screed once
Base stone compacts properly only in layers (lifts) of 2 to 4 inches: dump, rake, mist with water, run the plate compactor in overlapping passes both directions, repeat. A 6 inch base is two lifts, not one. The sand layer is never compacted before laying: screed it flat at 1 inch with a pipe and board, lay pavers directly on it, then the final plate compaction with a pad seats the pavers into the sand. Walking on screeded sand is the classic way to ruin a flat bed.
Edges and joints finish the job
Unrestrained pavers walk apart in two seasons, so every open edge needs plastic or concrete edge restraint spiked into the base layer, not into loose soil. Sweep joints full with polymeric sand for weed and washout resistance. Buying stone and sand separately for this build is nearly always cheaper than all in one bagged paver base products, which cost 3 to 4 times bulk price per cubic foot; the bulk math is exactly what the crushed stone and sand calculators are for.