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Patio Paver Base Calculator · Free calculator

12x20 Patio Paver Base Calculator

A 12' × 20' paver patio (240 sq ft) needs 3.41 yd³ — about 4.77 tons — of compacted gravel base at 4", plus 0.81 yd³ of bedding sand at 1". Here's every layer, bag count and paver quantity for 12x20.

Quick answer

4" gravel base
3.41 yd³ · 4.77 t
6" gravel base
5.11 yd³ · 7.16 t
1" bedding sand
0.81 yd³ · 44 bags
4x8 pavers (+10%)
1,188
Edge restraint
64 LF
Base rock (bulk) @ 4"
$193

▍Gravel Calculator

Material
ft
in
ft
in
in
Waste Factor
$
L = 20' 0"W = 12' 0"D = 4"
Cubic Yards
3.41yd³
incl. 15% waste · Bulk delivery: order 3.50 yd³
Cubic Feet
92.00ft³
Area
240.0sq ft
Weight
4.77tons
Weight
9,541lbs
Gravel bags needed
  • 0.5 cu ft bag (~50 lb) (0.5 ft³ yield)184

Gravel base for a 12x20 paver patio

240 sq ft, +15% for compaction. Crushed stone / Class II road base ≈ 1.4 tons per yd³.

Base depthUseCubic yardsTons0.5 cu ft bagsBulk est.
4"Patio / walkway (foot traffic)3.41 yd³4.77184$193
6"Patio on clay or in frost zones5.11 yd³7.16276$289
8"Paver driveway (vehicles)6.81 yd³9.54368$385

Sand, pavers & edging for 12x20

ItemQuantityNotes
Bedding sand 1" (concrete sand)0.81 yd³ / 1.10 tons44 × 0.5 cu ft bags
Standard 4" × 8" pavers1,1884.5 per sq ft + 10% cuts
Polymeric joint sand (50 lb)4~60 sq ft per bag
Edge restraint64 LF8 × 8' sections, spikes every 12"
Geotextile fabric264 sq ftextend 6" past edges
Excavation depth @ 4" base7.375"4" base + 1" sand + 2-3/8" paver

How the math works

  1. Area: 20 ft × 12 ft = 240 sq ft
  2. Base volume @ 4": 240 × (4 ÷ 12) = 80.00 cu ft
  3. Add 15% for compaction: 80.00 × 1.15 = 92.00 cu ft = 3.41 yd³
  4. Tons: 3.41 yd³ × 1.4 t/yd³ = 4.77 tons
  5. Sand @ 1": 240 × (1 ÷ 12) × 1.10 = 22.00 cu ft = 0.81 yd³
  6. Pavers: 240 sq ft × 4.5 × 1.10 = 1,188 pavers

Trade pro tips

  • A 12x20 patio (240 sq ft) at 4" base needs about 4.77 tons of base rock — have it dumped on a tarp near the dig.
  • Excavate base depth + 1" sand + paver thickness (2-3/8" for standard pavers).
  • Compact the base in 2" lifts with a plate compactor — one thick lift never gets dense.
  • Screed bedding sand to exactly 1". Thicker sand causes pavers to rut and shift.
  • Use edge restraint on every side not held by a wall or slab, spiked every 12".

Frequently asked questions

How much gravel base do I need for a 12x20 paver patio?

At 4" compacted: 3.41 yd³ (4.77 tons). At 6": 5.11 yd³ (7.16 tons). For a paver driveway at 8": 6.81 yd³ (9.54 tons). All include 15% for compaction.

How much sand do I need for 12x20 pavers?

A 1" bedding layer for 240 sq ft is 22.00 cu ft — 0.81 yd³, about 1.10 tons or 44 bags of 0.5 cu ft sand. Add ~4 bags of polymeric sand for the joints.

How many pavers for a 12x20 patio?

About 1,188 standard 4" × 8" pavers (4.5 per sq ft × 240 sq ft + 10% for cuts). Herringbone and other angled patterns can need 15% extra.

How deep should I dig for a 12x20 paver patio?

About 7-3/8" for a patio: 4" gravel base + 1" sand + 2-3/8" pavers. On clay or in frost zones use a 6" base (about 9-3/8" dig), which takes 5.11 yd³ of gravel for 12x20.