Paver calculator (US)
Count slabs or pavers including joint widths, then size the sub-base, bedding mortar, jointing compound and edge restraints for the whole build-up.
Set up for United States: USD prices, Sales tax, and imperial units with local product sizes.
Works in inches with US paver sizes, and defaults to a 3/8 in joint for slabs or 1/8 in for brick pavers.
US terminology throughout: pavers rather than paving slabs, gravel base rather than MOT Type 1, and prices in dollars with a sales-tax field you set yourself.
Your project
Showing United States units, product sizes and Sales tax.
Quick start
Patio area
Add a section for each part of the patio and subtract anything not being paved.
Pavers
All units the same size.
2,200 kg/m³
⅜ in is typical for pavers; ⅛ in for tight block paving.
Joints line up in both directions. The least wasteful pattern to cut.
The calculator warns you if this is below the recommended figure for your pattern.
Build-up and jointing
4 in for a pedestrian patio, 6 in or more over soft ground or for vehicles.
Standard for slabs. Estimated as sand and cement.
Block paving and sand-bedded paving must be restrained at every free edge.
Estimate updated. 123 pavers of 16.00 in × 16.00 in pavers required.
Patio and paving calculator
United States · Imperial units · 30 July 2026
Shopping list
5 lines- 123pavers16.00 in × 16.00 in paversConcrete paving, 2.00 in thick — about 18.5 kg each
- 4cubic yardsRoad base / Class II base4.00 in compacted
- 1.5cubic yardsConcrete sandFor a 1.50 in mortar bed
- 794 lb bagsCement1:5 cement to sharp sand bedding mortar
- 450 lb tubsBrush-in jointing compoundSold in tubs by weight. Fill joints to full slab depth for a durable joint.
Estimate results
What you measured
- Patio area
- 208.00 ft²
- 19.32 m²
- Laying pattern
- Straight grid (stack bond)
- Paving weight
- 2.50 tons (2.27 tonnes)
- approx. 3 pallets
What to buy
10% waste included| Material | Buy | Weight |
|---|---|---|
16.00 in × 16.00 in pavers Concrete paving, 2.00 in thick — about 18.5 kg each Rounding: The calculation requires 111.7 pavers. Adding 10% waste gives 122.87. Rounded up to 123 pavers. Main material | 123pavers | 2,270 kg |
Road base / Class II base 4.00 in compacted Rounding: The calculation requires 3.34 cubic yards. Adding 10% waste gives 3.67. Rounded up to the next 0.5 cubic yards to give 4 cubic yards. Base and membrane | 4cubic yards | 6,422 kg |
Concrete sand For a 1.50 in mortar bed Rounding: The calculation requires 0.96 cubic yards. Adding 10% waste gives 1.06. Rounded up to the next 0.5 cubic yards to give 1.5 cubic yards. Bedding and mortar | 1.5cubic yards | 1,835 kg |
Cement 1:5 cement to sharp sand bedding mortar Rounding: The calculation requires 5.53 94 lb bags. Adding 10% waste gives 6.08. Rounded up to 7 94 lb bags. Bedding and mortar | 794 lb bags | 299 kg |
Brush-in jointing compound Sold in tubs by weight. Fill joints to full slab depth for a durable joint. Rounding: The calculation requires 3.14 50 lb tubs. Adding 10% waste gives 3.45. Rounded up to 4 50 lb tubs. Consumables | 450 lb tubs | 91 kg |
Assumptions behind each line
16.00 in × 16.00 in pavers
- Each paver occupies a 16.38 in × 16.38 in module once the joint is included.
- Straight grid (stack bond): Joints line up in both directions. The least wasteful pattern to cut.
- Concrete paving taken as 2,200 kg/m³.
Road base / Class II base
- Includes a 1.3× compaction allowance.
- Lay and compact in layers no thicker than 100 mm (4 in).
Concrete sand
- Based on 1.6 tonnes of sand per cubic metre of 1:5 mortar, which allows for bulking.
Cement
- 320 kg of cement per cubic metre of 1:5 mortar, supplied in 94 lb bags.
- Mix only what you can lay before it goes off.
Brush-in jointing compound
- Joint volume is 4.5% of the surface area (0.06 yd³ (0.04 m³)), filled to the full slab depth.
- Jointing material taken as 1,600 kg/m³. Check the manufacturer's coverage table for your specific product.
Laying layout
How this was calculated
Patio area
plus Main area (16 × 13 ft) = 19.32 m²
= 208.00 ft² (19.32 m²)
Module size including joint
(16.00 in + 0.38 in) × (16.00 in + 0.38 in)
= 0.1730 m² per paver
- That is 5.78 pavers per m² (0.537 per ft²).
pavers required
The calculation requires 111.7 pavers. Adding 10% waste gives 122.87. Rounded up to 123 pavers.
= 123 pavers
Sub-base volume
208.00 ft² (19.32 m²) × 4.00 in × 1.3 compaction
= 3.34 yd³ (2.55 m³)
Mortar bedding
208.00 ft² (19.32 m²) × 1.50 in = 0.96 yd³ (0.74 m³) of mortar
= 1.18 t sand + 236 kg cement
- Mix ratio 1:5 cement to sharp sand.
Jointing volume
(1 − 0.9547) × 208.00 ft² (19.32 m²) × 2.00 in joint depth
= 0.06 yd³ (0.04 m³)
- Joints occupy 4.5% of the paved surface at a 0.38 in joint width.
Weight and delivery
Approximate weight
12.03 tons
Likely delivery
dump truck
- 12.03 tons needs a dump truck. Confirm access width, overhead clearance and where the driver can tip.
- Check that the delivery route can take the weight — block paving, drainage covers and soft verges are easily damaged.
Note: Approximately 3 pallets of paving
Safety and compliance
Material planning only
This estimate is for material planning only. Structural dimensions, foundations and compliance requirements should be checked by a qualified professional.
Check for buried services before digging
Call 811 before you dig. Utility locating is free in every US state and is required by law in most of them.
Data behind this estimate
| Assumption | Value | Source |
|---|---|---|
Crushed aggregate base / road base Dense-graded base material, the US equivalent of MOT Type 1. | 2,100 kg/m³range 1,950–2,200 | Mineral Products AssociationReviewed 2026-07-01 |
Compaction allowance for granular sub-base Order about 30% more loose material than the finished compacted depth. | 1.3 × loose volumerange 1.2–1.4 | National Highways (UK)Reviewed 2026-07-01 |
Sharp sand / concrete sand Damp sand bulks up in volume but the delivered weight is what you pay for. | 1,600 kg/m³range 1,500–1,700 | Mineral Products AssociationReviewed 2026-07-01 |
Sand required per m³ of 1:5 mortar Allows for bulking; damp sand delivered by weight is the practical ordering unit. | 1.6 tonnes/m³range 1.5–1.7 | British Standards InstitutionReviewed 2026-07-01 |
Default waste allowance Covers cutting, breakage, setting-out error and the odd unusable unit. | 10 %range 5–15 | How Much NeededReviewed 2026-07-01 |
Cost
Enter the prices your supplier quoted. This site does not hold or estimate supplier prices, so totals appear only once you fill these in.
Sales tax varies by state and locality, so it starts at 0%. Enter your own combined rate to include it.
No prices entered yet. Everything else in this estimate — quantities, weight, delivery and the shopping list — works without them.
Save, print or share
Create a share link
Generates a private link with a random, non-guessable address. Shared estimates are not indexed by search engines and expire automatically.
Looking for patio suppliers?
No supplier network is connected to this site yet, so there is nothing to show here. When one is, quote requests will appear in this space — and it will always be obvious which listings are paid placements.
How this calculator works
Every figure below is derived rather than looked up, so you can check it against your own numbers. Nothing is hidden behind a black box.
Unit count
Paving is counted by module, not by slab. A 600 × 600 mm slab with a 10 mm joint occupies a 610 × 610 mm module, so it covers 0.3721 m² rather than 0.36 m².
Ignoring the joint over-orders by about 3% on a 10 mm joint and by more on small units — which is why block paving calculations go wrong most often.
units = area ÷ ((unit length + joint) × (unit width + joint))
Pattern and waste
Each pattern carries a recommended minimum waste allowance: 5% for a straight grid, 7% for running bond, 10% for basket weave and 15% for herringbone, where every perimeter unit is a diagonal cut.
If you set a lower allowance than the pattern justifies, the estimate says so rather than quietly under-ordering.
Random-size packs
Mixed-size packs are estimated from the coverage printed on the pack, because the size mix differs between suppliers and no calculator can predict a layout for them. The estimate says this plainly instead of inventing a plan.
Bedding
A full mortar bed is converted to sand and cement at a 1:5 ratio, using 1.6 tonnes of sand and 320 kg of cement per cubic metre of mortar.
A sand screed carries a 1.1 compaction allowance because it consolidates under the plate compactor.
Jointing
Joint volume is derived from geometry: the proportion of the surface that is joint rather than slab, multiplied by the depth of the unit.
For a 600 mm slab with a 10 mm joint that is 3.3% of the area; for a 200 × 100 mm block with a 3 mm joint it is 4.4%. Small units need proportionally more jointing material, not less.
joint volume = area × (1 − unit area ÷ module area) × unit thickness
Common questions
- How many paving slabs do I need?
- Divide the patio area by the module area of one slab — that is the slab size plus one joint width in each direction — then add a waste allowance for cuts. A 20 m² patio in 600 × 600 mm slabs with 10 mm joints needs 54 slabs before waste, and 60 with a 10% allowance.
- How deep should a patio sub-base be?
- 100 mm of compacted sub-base for a pedestrian patio on firm ground, 150 mm over soft or clay subsoil, and 150–200 mm if vehicles will cross it. Remember to order roughly 30% more loose material than the compacted depth.
- How much waste should I allow for paving?
- 5% for a straight grid on a rectangular area, 10% for most real patios, and 15% or more for herringbone, circular features or any area with angled edges.
US product sizes and conventions
Common US paver sizes
- 16 × 16 in — the standard patio paver, about 0.54 per ft² with a 3/8 in joint.
- 12 × 12 in — lighter and easier on paths.
- 24 × 24 in large-format slabs; heavy enough to need two people or a suction lifter.
- 8 × 4 in brick pavers, usually laid in running bond or herringbone with tight joints.
US build-up
- 4 in of compacted dense graded base for a pedestrian patio, 6 in or more over soft soil or for vehicles.
- 1 in of screeded bedding sand for interlocking pavers, not compacted before laying.
- Edge restraints on every free edge — sand-set paving spreads without them.
- A slope of about 1/8 in per foot away from the house for drainage.
Jointing
- Polymeric sand swept into the joints and activated with water is the usual choice for pavers.
- Plain joint sand is cheaper but needs topping up more often.
- Compact the pavers into the bedding sand with a plate compactor and a protective mat before jointing.
UK version: Patio and paving calculator — metric units and UK product sizes →