How much gravel do I need for a patio?

For a standard residential patio at 4 inches deep, you need 1 cubic yard of crushed stone for every 81 square feet. A 12 ft × 14 ft patio needs ~2 cubic yards or 2.7 tons of #57.

What's the best gravel for a patio base?

#57 crushed stone is the most common all-purpose patio base — drains well, compacts firm. CA6 / 21AA / Class 5 (a dense-graded base with fines) compacts even harder and is preferred when you're laying pavers.

How deep should the gravel be under a patio?

4 inches of compacted crushed stone for a standard residential patio. 6 inches if you have clay soil, live in a freeze-thaw climate, or are placing a hot tub.

Do I need sand on top of the gravel for a patio?

Yes if you're dry-laying pavers or flagstone — 1 inch of concrete sand (not play sand) goes on top of the compacted gravel as a setting bed. For mortared patios, you go straight from gravel to concrete slab to mortar.

How much does a gravel patio cost?

Materials only: ~$1.00–$1.50 per square foot for a 4-inch #57 base. Add $0.50–$0.75 per sq ft for sand bedding, plus your pavers or flagstone on top. A 200 sq ft patio is roughly $200–$300 in aggregate.

Can I use pea gravel as a patio base?

Not as a base under pavers — pea gravel doesn't compact and shifts under load. As a loose top surface (a 'gravel patio' you walk on directly), pea gravel works well at 2–3 inches over a compacted #57 base.

Should I use fabric under my patio?

Yes — woven geotextile (not landscape fabric) under the gravel keeps soil from migrating up into the base, which is what causes patios to sink and become uneven over years.

Do I need gravel under a flagstone patio?

Yes. Flagstone over bare soil cracks, shifts, and fills with weeds within a season. Use 4 inches of compacted CA6/21AA or #57 stone, then 1–2 inches of bedding sand or stone dust to set the flagstone in.

What's the difference between a paver base and a patio base?

Same job, different finish. Both use 4 inches of dense-grade aggregate (CA6, 21AA, or crusher run) over compacted soil with geotextile. A paver base adds 1 inch of bedding sand on top. A loose-stone patio base often skips the sand and uses #57 stone directly as the walking surface.

Patio Gravel Calculator — Tons & Cost

How this calculator works for patios

A patio base is doing two jobs: spreading the load of pavers, furniture, and feet across the soil, and giving water a path to drain through instead of pooling under the surface. 4 inches of #57 crushed stone is the widely-accepted minimum for a residential patio on stable soil. Bump it to 6 inches if your soil is clay or you live in a freeze zone — see our depth guide for cold-climate adjustments.

The calculator above defaults to that 4-inch #57 spec. If you are laying pavers with a sand bedding layer on top, switch to the paver base calculator — that page handles both layers in a single shot.

Compact in 2-inch lifts

Don't dump 4 inches of stone and stomp it once. Lay 2 inches, compact with a plate compactor (rented at any tool yard), then the second 2 inches and compact again. The result is twice as stable as a single thick lift. Read more about why volumes shrink under compaction in our compaction & waste guide.

Recommended depth & material

Use	Depth	Material	Notes
Loose-gravel patio (no pavers)	4"	#57 crushed stone or pea gravel	Edge it to keep stones contained.
Flagstone patio (mortared)	4"	#57 crushed stone	Concrete slab on top, then mortar.
Flagstone patio (dry-laid)	4" + 1" sand	#57 base, concrete sand setting bed	Stones laid directly on screeded sand.
Paver patio	4" + 1" sand	CA6 base, concrete sand setting bed	See paver-base calculator for both layers.
Patio in clay or freeze zone	6"	#57 crushed stone	Deeper base resists frost heave.

How to measure a patio area

Most patios are rectangles or L-shapes. Either fits cleanly into the multi-area mode.

Stake the corners. Drive stakes at the four corners of the patio (or at every corner of an L-shape). Run string between them to define the exact footprint.
Measure the rectangle. Length × width of the main rectangle, in feet. If the patio is L-shaped or has a bump-out, treat each part as a separate rectangle.
Set the depth. 4" for a standard residential patio on firm soil. 6" if you have clay, freeze cycles, or are placing heavy furniture / hot tubs.
Confirm the material. #57 crushed stone is the default. Switch to CA6 or 21AA if your local supplier recommends a denser base for your soil type.
Add 10% buffer. 10% covers compaction (you'll lose ~15% of loose volume after compacting), spillage, and the inevitable extra inch in low spots.

Worked example: 14-ft × 16-ft patio

A typical entertaining patio: 14 ft × 16 ft = 224 sq ft at 4 inches deep.

Volume: 224 × 4 ÷ 324 = 2.77 yd³
Weight: 2.77 × 2,750 ÷ 2,000 = 3.81 tons
With 10% buffer: ~3.05 yd³ / 4.2 tons
Cost: at $50/ton delivered, ~$210 in stone, plus an $80–$150 delivery fee.

Add another 0.7 yd³ of concrete sand if you're laying pavers or dry-set flagstone on top.

Patio Gravel Calculator