Gravel & Aggregate Base Calculator
One cubic yard of gravel covers about 100 sq ft at 3 inches deep and weighs roughly 1.4 tons. Enter your dimensions to get exact tonnage, cubic yards, bag counts, and delivered cost — with a compaction allowance so your finished depth matches the plan.
Compacted base settles below loose volume — order extra so the finished depth is what you planned.
Pro Tips
- →Rule of thumb: 1 cubic yard of gravel covers ~100 sq ft at 3 in deep and weighs ~1.4 tons
- →Order 10-15% extra when the base will be compacted — compaction reduces loose volume
- →4 in of compacted base is the standard under residential slabs; driveways take 4-6 in
- →Compact in lifts of 2-3 in with a plate compactor — you cannot properly compact 6 in at once
- →Bulk delivery beats bags above roughly 1 cubic yard — a ton of bulk gravel costs about what 15-20 bags do
5.43 yd³ incl. compaction allowance · covers 400 sq ft
133 cu ft at the entered depth, before compaction allowance
Bags only make sense for small repairs — bulk delivery is far cheaper above ~1 yd³
Material Cost Estimate
Bulk pricing ($15-60/ton delivered) varies widely by material, region, and haul distance — call two local yards for real quotes. Density assumed 1.35-1.45 tons/yd³ by material.
That's typically a professional pour. See costs ↓
4 short emails from Dave: what a fair quote should land at for your slab, the scope changes that swing it ±$500, and whether DIY is actually cheaper at your volume. Reply anytime — he'll review your real quote.
For general step-by-step instructions, read our complete Gravel Under Concrete and How To Pour Concrete.
How Much Gravel Do You Need?
Gravel math is volume math: length × width × depth gives cubic feet, divide by 27 for cubic yards, then multiply by density (about 1.4 tons per cubic yard for gravel) to get the tons a supplier will actually quote you.
The rule of thumb worth memorizing: 1 cubic yard covers about 100 sq ft at 3 inches deep. Everything else scales from there.
| Coverage per cubic yard | Depth |
|---|---|
| ~160 sq ft | 2 in |
| ~100 sq ft | 3 in |
| ~80 sq ft | 4 in |
| ~55 sq ft | 6 in |
Base Depth by Application
Depth is not a style choice — it is set by what sits on top and what the soil underneath is like.
| Application | Compacted Depth | Notes |
|---|---|---|
| Under interior slab / garage floor | 4 in | IRC R506.2.2 base course requirement |
| Under patio slab | 4 in | 4-6 in on clay or poorly draining soil |
| Under driveway slab | 4-6 in | Vehicle loads; thicken on soft subgrade |
| Paver patio/walkway base | 4-6 in | Plus ~1 in bedding sand on top |
| Paver driveway base | 8-12 in | Often two materials: crusher run over larger stone |
| Gravel driveway (no concrete) | 8-12 in total | Built in 2-3 lifts of different stone sizes |
| Shed foundation pad | 4-6 in | Extend pad 1 ft beyond shed footprint |
| French drain envelope | varies | Use washed #57 — never material with fines |
If you are pouring concrete on top, size the slab itself with the concrete slab calculator and the base with this one — the two layers are ordered from different suppliers in different units, which is exactly how people end up over- or under-ordering one of them.
Tons vs. Cubic Yards: Which Unit to Order In
Bulk aggregate is almost always sold by the ton, while your project math naturally produces cubic yards — the conversion depends on material density:
| Material | Tons per yd³ | Typical Use |
|---|---|---|
| ¾″ washed gravel / pea gravel | ~1.4 | Drainage, decorative, walkways |
| Crushed stone #57 | ~1.35 | Drainage layers, pipe bedding |
| Crusher run / paver base (with fines) | ~1.4 | Compactable structural base |
| Sand (damp) | ~1.45 | Paver bedding, fill |
Moisture swings real-world weight by up to 10%, which is why two "identical" loads can weigh differently on the scale ticket. The calculator uses mid-range densities; your supplier's ticket is the final word.
Why You Order More Than the Hole Holds: Compaction
A base that will be compacted needs 10-15% more loose material than the finished volume, because a plate compactor consolidates the particles into the voids. Order exactly the geometric volume and your "4-inch base" finishes at 3½ inches.
Compaction itself has one iron rule: work in lifts of 2-3 inches. A plate compactor's energy only reaches so deep — dumping 6 inches and running the plate over it compacts the top and leaves the bottom loose, which is how slabs and paver patios settle a year later.
Bulk Delivery vs. Bags
Bagged aggregate (0.5 cu ft bags) exists for repairs and tiny jobs — the per-volume price is 3-6× bulk.
| Order size | Best option | Why |
|---|---|---|
| Under ~0.5 yd³ (~27 bags) | Bags | No delivery fee, haul in a car trunk |
| 0.5-1 yd³ | Either | Compare bag total vs. delivery minimum |
| Over 1 yd³ | Bulk delivered | $15-60/ton delivered beats ~$8-16/bag-equivalent |
Many yards have a 1-3 ton delivery minimum; a pickup truck can legally haul about half a ton to a ton depending on rating, which makes yard pickup a middle option for medium loads.
What Delivered Gravel Costs in 2026
Expect $15-60 per ton delivered for common base materials — the wide range is mostly haul distance and regional quarry access, not the stone itself. Decorative stone runs higher. Concrete, by comparison, runs $165-205 per cubic yard delivered — if you are budgeting the whole project, the concrete cost calculator covers the slab side.
Practical quoting tip: call two local yards with your tonnage and zip code, not your square footage. Yards quote tons; converting on the phone is where errors creep in.
Gravel Under Concrete: The Part Everyone Skips
The base course is structural, not optional filler. It spreads loads across weak spots in the subgrade, provides a capillary break so groundwater cannot wick into the slab, and gives a uniform bearing surface so the slab cures evenly. Our gravel under concrete guide covers soil types, vapor barriers, and when you genuinely can pour without a base — and if you are planning the pour itself, work through the how to pour concrete guide before the truck is booked.
For driveways and patios specifically, the driveway guide and patio guide cover the full build-up from subgrade to finish.