ContractorHandbook

How Many Pavers for a 20x20 Patio?

Pavers to buy

1,935 pavers

400 sq ft of patio, 4 by 8 in pavers, 6 in compacted base, 1 in bedding sand, ten percent waste.

It does not stop at a number.

When the figures look right, the paver material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.

waste10%patio area, sq ftpaver size plus the joint sets pavers per sq ftarea x pavers per sq ft, plus base stone and bedding sand
The pavers are the visible half of the job and the cheap half of the excavation. Under them sits six inches of compacted base and an inch of bedding sand, and both come off the same area, which is why they are on the material list.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Patio length20 ft
  • Patio width20 ft
  • Paver length8 in
  • Paver width4 in
  • Paver thickness2.375 in
  • Joint width0.0625 in
  • Compacted gravel base6 in
  • Bedding sand1 in
  • Waste allowance10 %

Pavers to buy1,935 pavers

Patio area400 sq ft
One paver covers0.227 sq ftface plus one joint
Pavers per sq ft4.4
Pavers before waste1,759
Base gravel, compacted7.41 cu yd
Base gravel to order8.89 cu yd20% added for compaction
Base gravel weight12.44 tons
Bedding sand1.23 cu yd3,334 lb
Polymeric sand, 50 lb bags4100 sq ft per bag
Edge restraint80 ft

The material list this produces

Pavers1,935
Base gravel, cu yd9
Bedding sand, cu yd1
Polymeric sand, 50 lb bags4
Edge restraint, ft80
Edging spikes80
Geotextile fabric, sq ft440

Patio size compared

Twenty feet across, the large end. Read the two right hand columns together: the area doubles between the top and the bottom of this table while the edge restraint does not come close to doubling, which is the one economy of scale a patio has.

Patio sizePavers to buyPatio areaEdge restraint
20 by 15 ft1,451 pavers300 sq ft70 ft
20 by 20 ft1,935 pavers400 sq ft80 ft
20 by 25 ft2,419 pavers500 sq ft90 ft
20 by 30 ft2,902 pavers600 sq ft100 ft
20 by 40 ft3,869 pavers800 sq ft120 ft

What else matters here

A 20 by 20 patio is 400 sq ft, and this is also the page for how many pavers cover 400 square feet, with one thing to watch: the area answers most of the question and it does not answer all of it.

Everything on this list comes off the area except the last line. The same 400 sq ft is 1,935 pavers, 8.89 cu yd of gravel, 12.44 tons and 4 bags of polymeric sand whatever shape it is. The edge restraint is not. It is 80 ft as this 20 by 20, 82 ft as a 25 by 16, 100 ft as a 40 by 10 and 116 ft as a 50 by 8 strip. Same patio area, forty five percent more edging at the far end of that range.

The reason is that a square encloses more area per foot of perimeter than any other rectangle, so a square patio is the cheapest shape to edge and every step away from square costs edging. It is a small line on a small patio and a real one here, and it is worth knowing in the other direction too: if the shape is fixed by the house and the patio has to be long and narrow, take the edging figure off the perimeter rather than off a rule of thumb about area, or the last few feet arrive a week late.

What this calculator assumes

  • The joint default is 1/16 of an inch because concrete pavers are cast with spacer nubs on the sides and that is the joint you get when they are set tight. A hand set joint at 1/8 or wider takes noticeably more polymeric sand, so type the joint you are actually laying.
  • Waste is 5 percent for a running bond laid square to the edges, 10 for most patios, and 15 or more for herringbone or a circle kit, because every angled cut throws away most of a paver.
  • Base gravel is quoted compacted. Crushed stone loses about a fifth of its loose volume under a plate compactor, so the order line adds 20 percent back.
  • Four inches of compacted base suits a foot traffic patio on good soil. Six is the common default, and eight to twelve is driveway and heavy clay territory.
  • Polymeric sand is the volume of the joints at the full thickness of the paver, at about 100 pounds per cubic foot.
  • Weights use 2,800 lb per cubic yard for crushed stone and 2,700 for bedding sand.

Questions people ask

How many pavers for a 20x20 patio?

1,935 pavers at 4 by 8 in over 400 sq ft, including a ten percent waste allowance.

How many pavers cover 400 square feet?

The same 1,935, along with 8.89 cu yd of gravel and 4 bags of polymeric sand. Only the edge restraint depends on the shape.

Does the patio shape change the materials?

Only the edging. 400 square feet needs 80 ft of edge restraint as a 20 by 20, 100 ft as a 40 by 10 and 116 ft as a 50 by 8. A square is the cheapest shape to edge.

Different numbers?

The paver calculator takes any dimensions you like and hands back the same list.

Other common sizes