Gravel Patio Calculator — How Much Gravel for a Patio?
Pre-set for a 3-inch decomposed-granite surface (≈1.4 tons/yd³). Calculate the base layer separately — set depth to 3 and switch to #411 for that run.
Gravel calculator
Density shown is an industry-typical value and varies by supplier — confirm before ordering.
You need
Includes +10% extra
36.0
cubic feet
1.33
cubic yards
1.87
tons (2,000 lb)
72
bags (0.5 cu ft)
≈ 0.76 m³
Estimated cost: $0.00 (at $0/ton)
Order 5–10% extra for compaction and settling — loose gravel always settles to less volume after compaction.
How much gravel does a patio need? A 12 ft × 12 ft gravel patio with a 3-inch surface needs 1.33 cubic yards of gravel — about 1.9 tons — plus 1.33 yards of compacted base underneath. Calculate each layer at its own depth above, add 5–10% for settling, and edge the patio to hold the gravel in place. Full layer recipe below.
Patio gravel depth: two layers, calculated separately
A gravel patio is a sandwich: 2–3 inches of decorative surface over 2–4 inches of compacted base — and each layer gets its own calculator run. The base carries load and blocks weeds; the surface is what you see and walk on. Skipping the base is the number-one reason gravel patios rut under table legs and grow grass by year two. The standard residential recipe:
- Subgrade — strip 5–7 inches of soil, level, slope ~1/4″ per foot away from the house.
- Landscape fabric — overlapped 12 inches; weed and mixing barrier.
- Base — 2–4 inches of #411 or crusher run, compacted.
- Surface — 2–3 inches of finish material, screeded and lightly compacted.
- Edging — steel, brick or timber, set an inch above the gravel.
In the calculator: run depth 3 with decomposed granite for the surface, then depth 3 with #411 for the base, and add the tonnages — a 12 × 12 patio works out to roughly 1.9 tons of DG plus 2.0 tons of base.
Best patio gravels: firm vs soft underfoot
Decomposed granite gives the firmest natural surface; pea gravel the softest look — pick based on furniture, not just color. Chairs with slim feet sink and slide in loose pea gravel, while DG compacts nearly like a rustic slab.
- Decomposed granite (≈1.4 t/yd³) — firm, golden, designer-favorite; best for dining sets.
- Pea gravel (≈1.4 t/yd³) — soft, rounded, casual; budget for wide furniture feet and edging.
- #411 / crusher run (≈1.5–1.6 t/yd³) — utility gray but rock-solid; often the base anyway.
- River rock (≈1.35 t/yd³) — accent borders only; too shifty under seating.
Curved outlines? Measure the widest length and width and treat it as a rectangle — the overrun roughly offsets the cut corners at patio scale.
What a gravel patio costs
In typical published US ranges, materials for a DIY gravel patio run $2–$6 per square foot — a 12 × 12 patio lands around $300–$900 in stone, fabric and edging. Bulk DG or #411 dominates the budget; bags multiply the stone cost several times. Professional installation commonly quotes $8–$20 per square foot. See our gravel cost guide and compare gravel vs mulch if you're weighing ground-cover options.
Frequently asked questions
How deep should a gravel patio base be?
Use 2–3 inches of decorative surface gravel over 2–4 inches of compacted base like #411 or crusher run. The calculator above handles the surface layer; run the base layer separately with its own depth.
What gravel is best for a patio?
Compactable decomposed granite or #411 makes firm patio surfaces; pea gravel looks softer under furniture but can shift. Avoid smooth river rock for dining areas — chairs sink and slide in rounded stone.
Do I need landscape fabric under a gravel patio?
Yes — landscape fabric under the base keeps gravel from sinking into soil and blocks weeds. Overlap seams 12 inches, pin edges, and cut slits only where plants must come through.