Gravel patio or walkway: which gravel, how deep, and how much to order

A gravel patio or path is two layers: a compacted base that carries the load, and a surface you walk on. Which surface you choose decides how firm it feels underfoot, how it drains and how much it costs. The depths below come from a decomposed granite producer, a stabilizer maker, the paver industry’s base specification and the US Access Board’s trail guidance; the quantities and prices come from the weights and list prices in our ledgers.

Which gravel for a patio or path

The clearest published test for a walking surface is the US Access Board’s: a firm surface “resists deformation by indentations”, a stable one “is not permanently affected by expected weather conditions and can sustain normal wear and tear”. Its construction tips for a surface that passes are “crushed rock (rather than uncrushed gravel)”, “rocks with broken faces (rather than rounded rocks)”, “a rock mixture containing a full spectrum of sieve sizes, including fine material”, “rock that passes through a ½-inch screen” and “rock material that is compacted in 3- to 4-inch layers”. Measured against that list, the three gravels people lay on patios behave very differently.

So the choice is a trade: DG gives the firmest surface and the smoothest walk, at the cost of compaction work and occasional top-ups; ¾ in crushed stone drains best and needs no compacting, but stays a loose layer; pea gravel is the softest to walk on and the one the accessibility test rules out. Pea gravel is also not the cheapest per ton in our price lists. Compare every type side by side under types of gravel.

How deep the base and the surface should be

Every published figure for a gravel walking surface puts it on a compacted base. Kafka Granite specifies a 3 in compacted surface of its pathway mix on 4–6 in of compacted road base for a “walking path or patio”, and 4 in on 8–12 in where vehicles drive; its wax-coated mix may go down at 2 in. Stabilizer Solutions’ installation sheet calls for 3 in (light traffic) or 4 in (heavy) of stabilized aggregate on 3 in of compacted DOT crushed road base. The paver industry’s Tech Spec 2 sets 4 in as the minimum compacted base under a pedestrian paver surface on well-drained soil, and the Access Board compacts tread material “in 3- to 4-inch layers”, “moist (but not too wet)”, with vibrating equipment.

The figures below use 4 in of base and 3 in of surface, the thinnest combination those sources support for foot traffic. Dig 7 in below the finished height, set the edging, compact the base, then spread and compact the surface. The Forest Service builds the trail version the same way: geotextile first, “retainer rocks or logs” to hold the edge, then “high-quality tread material as fill above the geotextile”.

How much gravel a patio or path takes

Volume is area × depth. Weights are the published supplier figures in our density ledger, recorded in September 2026: pea gravel 2,440–2,720 lb per cubic yard, DG 2,400–2,500 lb, ¾ in crushed stone 2,600–2,800 lb and road base 2,860–3,000 lb. Each cell gives tons at the lighter and heavier weight.

DG and road base lose volume when compacted; Kafka’s depths are measured after compaction, so order the loose volume your producer specifies for a given compacted depth (the decomposed granite calculator and the road base calculator carry those allowances). Bags make sense only for the smallest jobs: 3 in of pea gravel on a 3 × 20 ft path is 15 ft³, or 30 half-cubic-foot bags. For any other size, use the pea gravel calculator or the crushed stone calculator with your own dimensions.

What the stone costs

These are the per-ton medians of the list prices in our ledger (recorded September 2026): road base $43 across 8 lists, ¾ in crushed stone $42.75 (5), DG $52.95 (2) and pea gravel $56.98 (6). By the yard, pea gravel lists at $85.49 median and DG at $120.00. Delivery is extra on every list.

Two things move the real bill more than the material choice. Delivery: a patio’s worth of stone is a small load, and small loads pay the most per ton (see the dump truck load guide). And the base: it is heavier than the surface and, at these depths, costs more than the surface does, so skipping it is where a cheap patio becomes a soft one.

Edging, fabric and compaction

Edging holds the base and surface at their depth; without it the surface migrates into the lawn. Fabric between soil and base keeps the two from mixing; the extension services disagree about fabric under rock mulch (Colorado State says it is not needed at the right depth and woven fabric “eventually becomes clogged”; Utah State allows a fabric that passes air and water, never plastic), but under a trafficked base the trail guidance is to lay geotextile first. Compaction is what turns DG or road base from a pile into a surface: moist material, 3–4 in layers, a vibrating plate.

How these figures were worked out

• Stone (ft³) = length × width × depth ÷ 12; yd³ = ft³ ÷ 27; bags = ft³ ÷ 0.5, rounded up.
• Tons = yd³ × the lighter and heavier published weight ÷ 2,000; cost = tons × the per-ton median list price. No compaction or waste allowance; delivery excluded.
• Depths: 4 in base (ICPI pedestrian minimum; within Kafka’s 4–6 in) and 3 in surface (Kafka and Stabilizer Solutions).