Paver Calculator

Laying pavers for a 12 by 12 ft patio starts with one honest question: how much concrete do you actually need? This page answers it for paver calculator, using the cubic-yard formula and the typical bag yields in our material data. The result on this page is an estimate, not a guarantee: coverage, pack sizes, yields and prices vary by brand, product line, surface and region, and the label on the product you buy governs. Every figure below is shown as a range for exactly that reason, and the calculator on this page asks for your measurements instead of handing you a single magic number.

Pavers are counted by area plus waste, not by weight, and the pattern you choose decides how much cutting waste to expect. The rest of this page explains how the calculation works, shows a full worked example with its own measurements and a range result, gives cost guidance as ranges, and finishes with the steps to measure, order and check your delivery. Nothing here is a single exact number, because a single exact number would be dishonest: subgrades are uneven, forms flex, spillage happens, and a bag that yields one volume on paper can yield a little less once it is mixed and placed.

How the calculation works

The calculator needs three inputs, and each one changes the answer. First, the length and width in feet, measured at the longest and widest points of the form — for a rectangle that is a single multiplication, and for an L-shape or a footing run it is the sum of the separate rectangles. Second, the depth in inches, converted to feet by dividing by 12: a 4 in (10.2 cm) slab is one-third of a foot deep, a 6 in (15.2 cm) slab is half a foot, and an 8 in (20.3 cm) slab is two-thirds. Third, the waste allowance: our material data uses about 10% extra for waste, spillage and uneven subgrade as the typical allowance, because forms are never perfectly true and a little concrete always stays in the mixer, the wheelbarrow or the chute.

Pavers are counted one by one: a 12 by 12 in paver covers 1 sq ft, so a 144 sq ft patio needs 144 pavers before waste, and the typical waste range of 5–10% takes that to 152–159 pavers. Smaller pavers need more pieces per sq ft — divide the area by the area of one paver and add the same waste range.

The formula is short: cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27, because one cubic yard holds 27 cubic feet (0.76 cu m). Bagged mix follows from the same volume: one cubic yard takes about 45 bags of 80 lb (36.3 kg) mix or about 60 bags of 60 lb (27.2 kg) mix, typical yields from our material data — an 80 lb bag yields about 0.6 cu ft and a 60 lb bag about 0.45 cu ft. Multiply the cubic yards by 45 or by 60, add the 10% allowance, and round up to whole bags. Always round up: a pour cannot wait while someone fetches three more bags, and a short load costs far more than the spare bags would have.

Worked example: a 12 by 12 ft patio

Here is the full arithmetic for a 12 by 12 ft patio, with every step shown so you can check it against your own project.

Step 1 — gross area. 12 ft × 12 ft = 144 sq ft (13.4 sq m).

Step 2 — pavers before waste. At 1 sq ft per 12 by 12 in paver, that is 144 pavers.

Step 3 — add waste. At 5%: 144 × 1.05 = 152 pavers. At 10%: 144 × 1.10 = 159 pavers.

Step 4 — base and jointing sand. A paver patio sits on a compacted gravel base with jointing sand swept between the pavers — budget for both, and check the bag labels for coverage.

Result: 152–159 pavers for a 12 by 12 ft patio — buy the high end if the pattern is diagonal or the patio has curves. Buy a few extra bags beyond the high end if the subgrade is uneven or the forms are rough, and keep the spares dry — bagged mix that gets damp in storage is wasted money.

Cost guidance

Costs on this page are ranges, labelled typical retail range — check the current shelf price before budgeting. No single national price is quoted, because ready-mix and bagged concrete prices vary by region, supplier, mix strength and delivery distance, and a price that is right at one plant can be wrong at the next. The way to budget is to multiply, not to guess: take the cubic yards from the worked example, multiply by the shelf or quoted price per cubic yard for the mix you have chosen, then add delivery, any short-load fee for small orders, reinforcement such as rebar or mesh, and formwork and finishing tools if you do not own them.

Two cost traps catch first-time buyers. The first is ordering the low end of the range and then paying for a second small delivery — or a short-load fee — for the concrete that finishes the pour. The second is forgetting the extras: reinforcement, formwork, curing compound and finishing tools together are a meaningful share of a small job's cost, and a slab that needs excavation or a gravel base costs more before a single yard is poured. Compare the total, not the per-yard price, and get the quote against the same dimensions and depth you used for the volume count. Ready-mix usually beats bagged mix on price once the job passes about a cubic yard, while bagged mix wins for small repairs where a truck cannot justify the trip.

Step by step: measure, calculate, order

1. Measure twice. Measure the length and width in feet at the longest and widest points, and the depth in inches with a tape held against the form. Forms are rarely perfectly true — measure the depth in several places and use the deepest reading for the order.

2. Choose the mix and the method. Ready-mix suits jobs over about a cubic yard; bagged mix suits small pours and repairs. Check the bag label or the supplier's ticket for the mix strength and the yield per bag before you commit.

3. Use the calculator on this page. Enter the length, width and depth, and the tool returns a range in cubic yards and in bags. Plan on the high end — a pour cannot wait while someone fetches more mix.

4. Order and check the delivery. Order the high end of the range, confirm the delivery time and the access route for the truck, and have the forms, reinforcement and finishing tools ready before the concrete arrives.

5. Before you pour. Wet the subgrade lightly, check the forms are level and braced, confirm the reinforcement is in place, and make sure you have help, wheelbarrows and finishing tools within reach — concrete waits for no one.

Common mistakes to avoid

  • Ordering the low end of the range and then paying a short-load fee or a second delivery for the concrete that finishes the pour.
  • Measuring the depth once, at the shallowest spot, and under-ordering by a tenth of a yard or more.
  • Forgetting the 10% allowance for waste, spillage and uneven subgrade — the subgrade is never as flat as it looks.
  • Pouring without reinforcement, formwork checks or a curing plan — the volume count is only half the job.

Frequently asked questions

How many pavers do I need for a patio?

For the 12 by 12 ft patio on this page, 152–159 pavers at 1 sq ft per 12 by 12 in paver plus the typical 5–10% waste range. Smaller pavers need more pieces per sq ft — divide your area by the area of one paver and add the same waste range.

How much waste should I add for pavers?

The typical range is 5–10%: straight patterns in a rectangular patio sit at the low end, and diagonal patterns, curves and borders push you to the high end or beyond it.

What goes under pavers?

A compacted gravel base, a bedding layer of sand, and jointing sand swept between the pavers once they are laid. The base matters more than the paver count — a patio without a proper base will settle and shift.

Can I cut pavers myself?

Yes, with a masonry saw or a paver splitter, plus eye and ear protection. Measure twice and cut once — every cut is waste, which is why the waste allowance exists.

Do I need to seal my pavers?

Sealing is optional and depends on the paver material and the look you want; it can deepen the colour and slow staining. Check the product label for the sealer made for your paver type.

Related calculators

Results are estimates — verify with the product label. Coverage, pack sizes, yields and prices vary by brand, product line, surface and region; the label on the product you buy governs. Cost figures are typical retail ranges — check the current shelf price before budgeting.