Pedestal Paver Calculator
This free pedestal paver calculator turns your patio, terrace or rooftop dimensions into a shopping list: how many pavers, how many pedestals, what height range the pedestals must cover, and roughly how much load each pedestal carries.
How to Use This Pedestal Paver Calculator
Enter the length and width of the area in feet, pick your paver size, joint gap and material, and choose the design live load. Add the lowest pedestal height you need and the slope of the structure underneath. Press Calculate to get the pavers and pedestals to order, the pedestal height range, the estimated load on each pedestal, and a comparison of other paver sizes for the same area.
Why This Matters
Pedestal pavers sit on adjustable plastic or fiber-reinforced supports instead of sand or mortar. That makes them the go-to system for rooftop terraces, balconies, over-waterproofed slabs and uneven concrete patios, because water drains beneath the surface and you can still reach the membrane later. The catch is that every pedestal is a line item. A 20 × 12 ft terrace in 24 × 24 in pavers needs about 60 pavers but 77 pedestals, because the edge row and column need support too. At roughly $4–$12 per pedestal, miscounting by 10 percent is a real cost, and a short count stops the job because you cannot improvise a missing support.
Height and weight matter just as much. A drainage slope of 1% across 20 ft is 2.4 inches of difference, so the pedestals at one end must be that much taller than the other end, and a pedestal rated for 1 to 2 inches simply will not reach. Porcelain pavers are light, around 10 pounds per square foot, while 2-inch concrete pavers are about 25. On an elevated structure that difference, plus people and furniture, decides which pedestals and which framing you can use. Landscapers, deck builders, roofers and homeowners planning a weekend project all need these numbers before they order.
How It's Calculated
Everything is done in inches. With paver sides pw (along the length) and ph (across the width) and joint gap g:
- Columns: n = ⌈(L × 12 + g) ÷ (pw + g)⌉, and rows: m = ⌈(W × 12 + g) ÷ (ph + g)⌉. Any partial paver counts as a whole paver, because it is cut from a full one.
- 4-point pedestals: (n + 1) × (m + 1), since neighboring pavers share each corner pedestal.
- 6-point pedestals: the 4-point count plus one pedestal at the middle of each long edge, n × (m + 1) when the long side runs along the length.
- Order quantity: ⌈count × (1 + waste%)⌉ for both pavers and pedestals.
- Height range: the lowest height you entered (rounded down to ¼ in) up to that height plus slope% × the longer side, rounded up to the next ¼ in. Assuming the slope runs along the longer side is the worst case.
- Load per pedestal: (paver dead load + live load, in psf) × paver cell area in ft², rounded up to the next 10 lb. This assumes every pedestal carries one full paver cell, which overstates the load on a 4-point or 6-point layout on purpose.
Live loads follow the common values in IRC Table R301.5 (40 psf decks, 60 psf balconies) and IBC Table 1607.1 (100 psf assembly areas). Material weights are typical figures; use the manufacturer's data sheet for real products. Local codes vary, and this tool is a planning estimate, not engineering, permit or inspection approval.
Worked Example
A 20 × 12 ft terrace, 24 × 24 in porcelain pavers (2 cm, 10 psf), 1/8 in joints, 10% waste, 60 psf live load, 2 in minimum pedestal height, 1% slope.
- Columns: (240 + 0.125) ÷ 24.125 = 9.95, so n = 10. Rows: (144 + 0.125) ÷ 24.125 = 5.97, so m = 6.
- Pavers in the layout: 10 × 6 = 60 (45 full, 15 cut). With 10% waste: 60 × 1.1 = 66 pavers to order.
- Pedestals: 11 × 7 = 77, and 77 × 1.1 = 84.7, so order 85.
- Height: 1% × 240 in = 2.4 in of slope, so the range is 2.00 to 4.50 in (4.4 rounded up).
- Load: cell area = 24.125² ÷ 144 = 4.04 ft². (10 + 60) × 4.04 = 283 lb, rounded up to 290 lb per pedestal.
- Edge restraint: 2 × (20 + 12) = 64 ft.
Tips & Common Mistakes
- Forgetting the edge row of pedestals. A grid of n × m pavers needs (n + 1) × (m + 1) supports, not n × m.
- Ignoring slope. Measure the high and low points of the substrate. If the range exceeds one pedestal's adjustment, you need taller pedestals or slope-correcting heads. Our slope converter helps turn inches-per-foot into percent.
- Using 4-point support under large pavers. Long pavers such as 24 × 48 in typically need mid-edge support. Follow the paver manufacturer's span rules.
- Skipping edge restraints. Perimeter pavers can drift or tip without a restraint or a curb, especially on rooftops.
- Measuring to the inch and trusting the answer. If a dimension is just a hair over a whole number of pavers, you get a thin sliver cut. Consider shifting the layout so both edges get a wider cut.
Frequently Asked Questions
How many pedestals do I need per paver?
With standard 4-point support, you need about one pedestal per paver in the field, because each pedestal sits under four corners. Add one extra row and one extra column of pedestals around the edge. With 6-point support, expect about two per paver.
How many pedestals do I need for 24 × 24 pavers?
Count the pavers across (n) and down (m), then multiply (n + 1) × (m + 1). A 10 × 6 grid of 24 in pavers needs 77 pedestals before waste. This calculator does that count and adds your spare percentage.
How do I handle a sloped substrate?
Keep the paver surface level or sloped as you design it, and let pedestal height absorb the substrate slope. Multiply slope by run to get the height difference, then pick pedestals whose adjustment range covers the minimum to maximum height, using slope-correcting heads where the manufacturer allows.
How much weight can a paver pedestal hold?
Ratings vary widely by product, from about 1,000 lb to several thousand pounds per pedestal. Compare the estimated load shown here with the manufacturer's published capacity, and choose a rating comfortably higher.
Do pedestal pavers need a permit or engineer?
It depends on where you live and where you build. Ground-level patios often do not, while elevated decks, balconies and rooftops usually require a check of the structure's capacity. Ask your local building department; this calculator does not replace that review.
How much waste should I allow?
Ten percent is a common starting point for simple rectangles, covering cuts and breakage. Use 15–20% for diagonal layouts, small areas, or fragile materials, and keep a few spare pedestals for height mistakes.