Patio Calculator
Estimate complete multi-layer material takeoffs for patios: poured concrete slabs, interlocking brick pavers, or crushed stone gravel with base layers and edging.
Calculation Results
The net square footage of the patio surface.
Total linear feet of border edge restraints or wooden form boards.
Total individual paving stones needed including cutting allowance.
Tons of compacted crusher run (#57) gravel base needed under pavers.
Tons of coarse ASTM C33 concrete sand for the 1-inch bedding layer.
50 lb bags of polymeric locking joint sand to prevent weeds.
Ready-mix concrete volume required in cubic yards.
Number of standard 80 lb bags if mixing concrete on site.
Total tons of decorative pea gravel or crushed stone for the patio bed.
Estimated total material and construction budget based on selected rate.
How This Calculator Works
Plan your outdoor living space with these simple steps:
- Measure the Footprint: Enter patio length and width.
- Select Patio Type: Choose between an interlocking paver system, a poured concrete slab, or a gravel patio.
- Review Full Material Schedule: For pavers, you receive quantities for surface stones, base rock, bedding sand, edge restraints, and polymeric sand.
Formula & Calculations
A durable patio requires proper structural layering following Interlocking Concrete Pavement Institute (ICPI) and ACI building standards:
1. Interlocking Paver System Layers
- Subbase Gravel: 4 inches of compacted aggregate (
Area × 0.33ft × 1.15 compaction). - Bedding Sand: Exactly 1 inch of coarse concrete sand (
Area × 0.083ft × 1.10). - Pavers: Calculated from nominal piece area (4.5 units/sq ft for 4"x8" brick pavers).
- Polymeric Joint Sand: 1 bag per 75 sq ft sweeps into joints to lock stones together.
- Border Restraint: Plastic snap-edge pinned along the perimeter prevents lateral creep.
2. Poured Concrete Patio Slab
Cubic Yards = [Area (sq ft) × Thickness (ft) × 1.10 Waste] / 27
A standard 4-inch patio requires 1 cubic yard of concrete for every 81 square feet.
Step-by-Step Calculation Examples
Backyard Paver Patio (20ft x 12ft, 4x8 Pavers)
Complete 240 sq ft paver patio takeoff with 4" gravel base and 1" sand bedding at $15/sq ft.
- length: 20
- width: 12
- material_type: pavers
- paver_size: 4x8
- waste: 10
- cost_per_sqft: 15
- area: 240.0 sq ft
- perimeter: 64 ft
- pavers_needed: 1188
- paver_base_gravel: 4.83 ton
- paver_sand_bed: 1.14 ton
- poly_sand_bags: 4
- estimated_cost: $3,600.00
Frequently Asked Questions
Which is cheaper: a concrete patio or a paver patio?
A basic poured concrete slab is generally cheaper upfront ($6 to $12 per sq ft installed) compared to pavers ($15 to $30 per sq ft installed). However, pavers offer lower long-term repair costs because individual stones can be lifted and re-leveled without destroying the patio.
How thick should a concrete patio slab be?
4 inches is the standard thickness for residential concrete patios. If you plan to install a hot tub, brick pizza oven, or heavy stone outdoor fireplace, pour a 6-inch slab reinforced with #4 rebar.
Why do pavers need both gravel and sand underneath?
The 4-inch compacted gravel base provides structural load support and channels rainwater away to prevent frost heaves. The 1-inch sand layer provides a smooth screeded bed to level the pavers without disturbing the compacted base.
Can I install a paver patio directly over an existing concrete slab?
Yes, provided the concrete slab is structurally sound with no major cracks or settling. You can lay 1-inch thick overlay pavers directly over the concrete using adhesive along the perimeter border.
What is the purpose of edge restraints on a paver patio?
Edge restraints (rigid plastic or aluminum snap-edging spiked into the ground with 10-inch steel spikes) prevent perimeter pavers from shifting outwards under foot traffic, keeping the entire interlocked system tight.
How much slope should a patio have for water drainage?
A patio should always slope away from the house foundation at a rate of 1/4 inch per foot (approx. a 2% grade) so that rainwater sheds away from the home.