Gravel Grid / Paver Base Calculator
Enter the paved area’s length and width, pick a project type or custom depth, and choose a base material to see the tons and cubic yards you need.
Measure straight across the widest point.
Adjust depth below if needed.
Covers spillage and compaction. 5–10% is normal.
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Bags or bulk delivery?
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Coverage & weight
Material profile
For the calculator’s default 20 ft × 15 ft gravel grid base at 4 inches deep, you’ll need about 4.07 cubic yards, or roughly 5.5 tons of open-graded aggregate including a 10% waste allowance. That’s around 221 bags if you’re buying small quantities by the bag instead of in bulk.
Base aggregate needed for common gravel grid and paver projects
These estimates use open-graded aggregate (No. 57) at 2,600 lb per cubic yard with a 10% waste allowance built in.
| Project | Depth | Cubic yards | Tons |
|---|---|---|---|
| Small paver patio base, 150 sq ft | 4 in | 2.04 yd³ | 2.65 tons |
| Gravel grid driveway apron, 400 sq ft | 4 in | 5.43 yd³ | 7.06 tons |
| Vehicle-traffic paver base, 600 sq ft | 6 in | 12.22 yd³ | 15.89 tons |
| Large parking pad base, 1,000 sq ft | 6 in | 20.37 yd³ | 26.48 tons |
| Walkway base, 80 sq ft | 4 in | 1.09 yd³ | 1.41 tons |
Base material types, density and drainage
| Type | Weight per yd³ | Best for | Drainage |
|---|---|---|---|
| Road base / crusher run (Type 1) | 2,900 lb | Standard compacted sub-base | Low |
| Open-graded aggregate (No. 57) | 2,600 lb | Permeable paver / gravel grid systems | Excellent |
| Aggregate base course (ABC) | 3,000 lb | Driveways under grids or pavers | Moderate |
Figures are for dry material. Wet or freshly delivered material can weigh noticeably more.
How to calculate base aggregate you need
- Measure the area length × width in feet for the paved or grid footprint, or radius² × π for a circular one.
- Set the compacted depth 4in under a gravel grid or foot-traffic pavers, 6in or more under a driveway.
- Convert to cubic yards multiply area by depth in feet to get cubic feet, then divide by 27.
- Add waste add about 10% for compaction settling and spillage while spreading and screeding.
- Convert to tons multiply cubic yards by the material’s density (2,600-3,000 lb/yd³) and divide by 2,000.
Worked example
Using the calculator’s default 20 ft × 15 ft gravel grid base at 4 inches deep with open-graded aggregate:
- Area20 ft × 15 ft = 300 sq ft
- Depth in feet4 in ÷ 12 = 0.33 ft
- Volume300 sq ft × 0.33 ft = 100 cu ft
- Plus 10% waste100 × 1.10 = 110 cu ft
- Cubic yards110 ÷ 27 = 4.07 yd³
- Weight (open-graded aggregate, 2,600 lb/yd³)4.07 × 2,600 = 10,592.6 lb
- Tons10,592.6 ÷ 2,000 = 5.30 tons
- Order amountround up to 5.5 tons, or about 221 bags at 0.5 cu ft each
Recommended depth by project
| Project | Recommended depth | Notes |
|---|---|---|
| Gravel grid base | 4 in | Standard depth for permeable gravel-grid paver systems |
| Paver base, foot traffic | 4 in | Patios and walkways carrying pedestrian loads only |
| Paver base, vehicle traffic | 6 in | Driveways and areas that see car or light-truck weight |
| Heavy-duty / commercial base | 8-10 in | Parking areas or soft subgrade needing extra support |
| Thin leveling course | 2-3 in | Screed layer under lightweight edging or stepping stones |
Bags or bulk delivery?
Bagged base aggregate (roughly 0.5 cu ft per bag) works for a small paver repair or setting a single stepping stone, but it’s a poor value once you’re basing an actual patio or driveway. Compacted base needs consistent, even coverage, and bulk delivery makes that far easier than opening dozens of bags.
- Small repairsunder 1 ton (about 40 bags) — bags avoid a delivery minimum for a tiny patch or single-slab job.
- Medium jobs1 to 5 tons — compare total bag cost against bulk price plus the delivery fee before deciding.
- Large jobsover 5 tons — bulk delivery is always cheaper and much easier to compact evenly.
Common mistakes
- Using open-graded stone where dense-graded is neededclean, gap-graded stone drains well but won’t compact as hard as a dense-graded base with fines — match the material to whether drainage or load-bearing matters more.
- Skipping geotextile fabricon clay or soft soil, base aggregate sinks into the mud without a fabric separation layer, and the base loses depth and strength over time.
- Not compacting in liftsplacing more than about 4 inches at once often leaves the bottom of the layer under-compacted, even with a plate compactor.
- Confusing loose and compacted depthdelivered aggregate is loose and settles 20-25% once compacted, so ordering by the finished compacted depth (as this calculator does) is correct.
- Undersizing base under gravel gridsgrids rely on the base beneath them for load transfer — skimping on depth lets the grid cells flex and the gravel migrate out.
- Ignoring edge restraintwithout a firm edge, compacted base and paver grids spread outward under traffic, especially on driveways.
What this calculator assumes
Adjust your result if your project differs from these.
- Depth is the compacted (finished) depth, not the loose delivered depth.
- Density assumes standard graded or open-graded aggregate compacted to typical density.
- 10% waste covers spillage, over-excavation, and compaction loss.
- Prices are material only; delivery, compaction equipment, and fabric are separate.
- Subgrade is assumed graded and free of standing water before base placement.
- Bag coverage assumes 0.5 cu ft bags; bulk is more economical above roughly 1 ton.
Common questions
How deep should base be under a gravel grid?
4 inches compacted is standard for foot traffic; go to 6 inches or more under a driveway or any area vehicles will cross.
What's the best material for a permeable paver base?
Open-graded aggregate like No. 57 stone drains freely with almost no fines, which is why it’s preferred under permeable gravel-grid and paver systems.
Can I use regular gravel instead of road base under pavers?
You can, but road base (with fines) compacts harder and holds shape better under load; open-graded stone is chosen specifically when drainage matters more than rigidity.
Do I need fabric under a gravel grid base?
Recommended on clay, sand, or any soil that pumps mud when wet — fabric keeps the base from mixing into the subgrade over time.
How much does base aggregate compact down?
Loose aggregate settles roughly 20-25% once compacted, which is why this calculator’s depth is the finished compacted depth, not the loose spread depth.
How many tons are in a cubic yard of base aggregate?
About 1.3 to 1.5 tons, depending on the material — open-graded stone runs about 2,600 lb/yd³, road base about 2,900-3,000 lb/yd³.
What depth of base do I need for a driveway with pavers?
6 inches compacted is the typical minimum for passenger vehicles; add more over soft or wet subgrade.
How much base aggregate do I need for a 300 sq ft patio?
At a 4-inch compacted depth with a 10% waste allowance, a 300 sq ft patio needs about 4.07 cubic yards, or roughly 5.5 tons — the calculator’s default example.
Should I compact the base in one pass or multiple lifts?
Compact in lifts no thicker than about 4 inches; a single deep lift often leaves the bottom under-compacted even with a good plate compactor.
Can gravel grids sit directly on native soil?
Not recommended for anything beyond very light foot traffic — a compacted aggregate base spreads the load and keeps the grid from flexing or sinking.
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materialcalculate.com/tools/gravel-grid-paver-base-calculator/
Project
| Shape | — |
| Dimensions | — |
| Depth | — |
| Area | — |
| Material | — |
| Waste allowance | — |
Volume & weight (incl. waste)
| Cubic yards | — |
| Cubic feet | — |
| Weight | — |
| Tons (rounded up) | — |
Shopping list
| Bulk order | — |
| Bagged alternative (0.5 cu ft) | — |
| Estimated cost | — |
Notes
Estimate generated by materialcalculate.com. Assumes uniform depth and standard dry material densities. Confirm quantities with your supplier before ordering.