Paver Calculator

How paver patios and driveways actually go in

Pavers don't sit on dirt — they sit on a four-layer stack of materials that together absorb load, drain water, and resist freeze-thaw movement. Get the stack wrong and you get a gorgeous patio that develops 1″ ruts in two summers. Get it right and the same materials will look the same in 30 years. The calculator above quantifies the shopping list; this section explains why each layer is in the stack and how to build it.

The full stack, top to bottom

1. Polymeric sand — fills the joints between pavers. Sweeps in dry, activates with water mist, hardens to a firm-but-flexible bond. Locks pavers laterally so they don't separate; sheds water; resists weed germination. About 1 bag per 90 sq ft (8.4 m²) for joints; double that for wider gaps or larger pavers.
2. Pavers (40–60 mm thick) — concrete, clay brick, or natural stone. Patio pavers are typically 40–50 mm; driveway pavers must be 60+ mm to handle vehicle loads.
3. Bedding sand (1 in / 2.5 cm) — coarse, washed, angular sand (not play sand). Screeded flat as a setting bed; lets you fine-tune the height of each paver.
4. Compacted crushed-stone base — 4 in (10 cm) for patios/walkways, 6 in (15 cm) for driveways, in 2-in (5 cm) lifts. This is the structural layer.
5. Subgrade (your native soil) — excavated, graded, and compacted before any base goes in.

Total excavation depth = paver thickness + 1 in sand + 4–6 in base. For a typical 50 mm patio paver on a 4-in base: about 7 in (18 cm) of dirt removed.

Coverage and paver count

Pavers are sold individually or by pallet. Common sizes and their coverage:

Add 5% waste for straight cuts, 10–15% for diagonal patterns or curved edges. Pallets typically hold 100–150 sq ft.

The math, walked through

For a 12 ft × 14 ft patio with 4″ × 8″ pavers and a 4-in base:

1. Patio area: 12 × 14 = 168 sq ft.
2. Pavers needed (with 5% waste): 168 × 1.05 ÷ 0.22 = ~801 pavers.
3. Base gravel volume: 168 × (4 ÷ 12) = 56 cu ft = 2.07 cu yd.
4. Bedding sand volume: 168 × (1 ÷ 12) = 14 cu ft = 0.52 cu yd.
5. Polymeric sand: 168 ÷ 90 = 2 bags.

Why driveways need more base than patios

A patio sees foot traffic — distributed loads in the 100–200 lb range. A driveway sees a 4,000-lb vehicle's weight concentrated on four tire patches the size of dinner plates. The pressure under each tire is 5–10× higher than under a person. Without enough compacted base, that pressure pushes individual pavers down into the subgrade, creating ruts where the tires sit.

• Patios: 4 in compacted base, 40–50 mm pavers.
• Walkways: 4 in base, 40–50 mm pavers.
• Driveways: 6 in base (in 2 × 3-in lifts), 60+ mm pavers.
• Heavy commercial: 8–12 in base + geotextile fabric.

The 60 mm driveway paver isn't optional — 50 mm pavers will crack under repeated wheel loads, especially at the wheel paths.

Edge restraint — the layer most DIYers skip

Without an edge restraint, the perimeter pavers slowly migrate outward each freeze-thaw cycle. Within 5 years, your patio looks like a melted ice cube. Edge restraint options:

• Plastic paver edge (DIY favorite) — 8-ft strips spiked into the base gravel. Cheap (~$10/strip), works fine for patios. Visible if you don't bury under sod.
• Aluminum or steel edge — more rigid, better for curves and driveways. ~3× the price.
• Concrete haunch (pro) — a buried strip of concrete poured against the back of perimeter pavers. Permanent, invisible, almost impossible to skip on driveways without code issues.

Drainage — slope, never flat

Every paver installation needs a slope to shed water — typically 1/4″ per foot (2%) away from buildings. Flat patios pond water, water freezes, freeze-thaw heaves individual pavers. Set the slope at the base-gravel stage; the pavers follow the base.

For driveways: slope toward the street, not toward the garage. A reverse-slope driveway funnels rainwater under the garage door — a problem to fix once, not forever.

Patterns — and why they affect waste factor

• Running bond / brick pattern — half-offset rows. 5% waste, easiest cuts (every other row needs a half-paver to start).
• Stack bond — pavers aligned in a grid. Lowest waste (3–5%) but visually static; less structurally interlocked.
• Herringbone (45° or 90°) — interlocking V pattern. Highest structural strength under load; required pattern for paver driveways per most manufacturers. 10–15% waste due to angled cuts.
• Basketweave — pairs of pavers alternating horizontal/vertical. Decorative; mid-waste (8–10%).
• Random / Roman cobble pattern — multiple paver sizes deliberately mixed. Pre-pallet kits are the simplest path here; expect 12–15% waste.

Common mistakes that ruin a paver install

• Skimping on base gravel. 2 in instead of 4 in might "look fine" right now — it won't survive winter. The base does all the work; underinvesting here is the most expensive shortcut on the planet.
• Compacting in one big lift. Add base in 2-in lifts and compact each one. Otherwise the bottom 2 in stays loose forever.
• Using play sand or fine sand for bedding. Play sand is too fine — it migrates between pavers under load and the surface settles. Use coarse, washed, angular sand (concrete sand or paver sand specifically).
• Skipping the edge restraint. Patio looks great year 1. By year 5, the perimeter has spread 1–2 inches in every direction.
• No fabric over poor subgrade. Clay subgrade pumps water up through gravel during freeze-thaw, mixing fines into your base. A geotextile (non-woven landscape fabric) under the base prevents this.
• Polymeric sand at the wrong moisture. Apply when pavers are bone dry, then mist the joints with a gentle shower setting until the sand surface barely darkens. Too much water turns it to concrete on top of the pavers and creates haze; too little and it never sets.

Pro additions

• Geotextile fabric. Standard practice on clay or organic subgrades. ~$0.10–$0.20/sq ft. Doesn't replace base depth; works alongside it to keep fines from migrating.
• Permeable pavers + open-graded base. Manage stormwater; some municipalities allow these to count against impervious-surface limits. Different base spec — open-graded #57 stone, no bedding sand, larger joints filled with #8 stone.
• Bedding sand stabilization. Some pros use a thin coat of polymeric "wet stabilizer" or epoxy on the bedding sand under driveway pavers to prevent migration. Adds ~$0.30/sq ft, extends life dramatically.
• Sealing. A penetrating sealer 30 days after install (for color enhancement) or wet-look sealer for sheen. Re-seal every 3–5 years. Optional for utility surfaces, recommended for visible patios.

Frequently asked questions