How to Use the Paver & Patio Base Calculator
Step 1: How to measure
Measure the finished patio or walkway in feet. Then add 6 inches to each side for the base layer, because a properly built patio has compacted gravel that extends beyond the pavers to support the edge restraint. For curved patios, measure the widest length and width as a bounding rectangle — the 5% cut allowance plus that rectangle usually covers curves.
Choose your paver size from the nominal dimension printed on the pallet. A 4×8 in brick paver gives 4.5 pavers per square foot, while a 12×12 in paver covers exactly 1 square foot. Base depth is typically 4 inches for patios and walkways, and 6–8 inches for anything that sees vehicle traffic.
Step 2: The exact formula
Paver count is area in square inches divided by the face area of one paver, plus 5% for cuts and breakage. Paver base volume is area × base depth ÷ 12, sold in 0.5 cu ft (roughly 50 lb) bags. A 1 inch screeded layer of leveling sand sits on top of the base.
Polymeric sand coverage depends on joint length: smaller pavers have more joints per square foot. We estimate about 30 sq ft per 50 lb bag for 4×8 pavers, rising for larger units. Joint width and depth change real coverage, so check your bag label.
Pavers = (Area ft² × 144 ÷ (paver W × L)) × 1.05 Base bags = (Area × Depth in ÷ 12) ÷ 0.5 Poly sand bags = Area ÷ coverage
Pro DIY tips
- Compact the base in 2 inch lifts with a plate compactor — never dump 4 inches and compact once.
- Slope the patio 1/8 inch per foot away from the house for drainage.
- Use screed rails (1 inch pipe) to get a perfectly flat sand bed, and never walk on screeded sand.
- Install plastic or aluminum edge restraint before sweeping in polymeric sand.
- Apply polymeric sand only when dry and no rain is forecast for 24 hours, then mist lightly to activate.
Frequently asked questions
How many pavers do I need for a 12×12 patio?
A 144 sq ft patio needs about 152 pavers of 12×12 in, or about 680 brick pavers (4×8 in), including 5% for cuts.
How deep should paver base be?
Use 4 inches of compacted paver base for patios and walkways, and 6–8 inches for driveways or clay soils.
How many bags of paver base per square foot?
At 4 inches deep, each 0.5 cu ft bag covers about 1.5 sq ft, so plan on roughly 0.67 bags per square foot.
How much area does a bag of polymeric sand cover?
A 50 lb bag covers roughly 30–75 sq ft depending on paver size and joint width — narrow-jointed large pavers use the least.
Do I need sand under pavers?
Yes. A 1 inch layer of coarse concrete sand on top of compacted base lets you bed and level each paver precisely.