Guide
Gravel Cubic Yards by Project Type
Published July 19, 2026
'How much gravel do I need' doesn't have one right depth — a walkway, a driveway base, and a drainage bed each call for a genuinely different depth because they carry different loads and serve different purposes, and using one flat depth across all three either wastes material or under-builds a structural base.
Walkway base
A pedestrian walkway typically needs a modest compacted base, often in the 2-3 inch range, since it only has to support foot traffic — enough to provide drainage and a stable, level surface for pavers or stepping stones without the heavier compaction requirements of a vehicle-bearing surface.
Driveway base
A driveway (or any vehicle-bearing surface) needs a substantially deeper base, commonly 4-6 inches, sometimes built and compacted in two separate lifts rather than one loose layer, since vehicle weight — especially repeated weight from regular use — needs a well-compacted, load-bearing base to prevent rutting and settling over time. Local soil conditions and frost depth can call for an even deeper base in some regions.
Drainage bed
A drainage bed (around a downspout discharge, a French drain, or a dry well) often uses a different, more open-graded stone than a walkway or driveway base specifically because the goal is water movement, not just a stable surface — open-graded stone has larger gaps between individual pieces that let water pass through quickly rather than compacting into a dense, less permeable base. Depth for a drainage bed depends heavily on the specific drainage design rather than following a single standard figure.
Decorative and top-dressing gravel
A decorative gravel top-dressing (over a landscape bed, for instance) is a different application from any of the structural uses above — it's typically applied at a shallow depth (1-2 inches) purely for appearance and modest weed suppression, over landscape fabric rather than a compacted structural base, and uses a completely different depth figure than a walkway or driveway base despite also being measured in the same cubic-yard formula.
Sizing the order
Once you've matched depth to your specific project type, the gravel calculator converts area x depth to cubic yards and then to tons using your stone type's actual density figure, since crushed stone, river rock, and decomposed granite all pack to different weights per cubic yard.
For a driveway spanning a long run, consider ordering in stages if the total tonnage would otherwise require multiple truck trips anyway — spreading delivery across the project's actual work schedule (base layer first, finish layer once the base is compacted and confirmed) can reduce how much material sits exposed to weather before it's used.
Gravel for a shed or outbuilding base
A gravel pad under a shed or small outbuilding is its own project type, typically needing a depth between a walkway and a driveway (often 4 inches) since it supports a stationary structure's weight rather than repeated rolling vehicle loads — check the specific structure's footprint and any manufacturer guidance, since some prefabricated shed kits specify their own minimum base depth and compaction requirement.
Playground and fall-zone gravel
Gravel or engineered wood fiber used as a fall-surface material under playground equipment has its own depth standard set by safety guidelines (often a minimum of 9-12 inches for pea gravel under equipment with a meaningful fall height), which is a genuinely different depth category from any of the structural or decorative uses above, driven by impact-attenuation requirements rather than drainage or load-bearing needs.
FAQ
Can I use the same gravel depth for a walkway and a driveway?
Not recommended — a driveway carries vehicle weight that a walkway's foot-traffic-only base doesn't need to support, so using a walkway's shallower depth under a driveway risks the base rutting and settling under regular vehicle use.
Does drainage-bed stone need to be compacted like a driveway base?
No, and compacting it would work against the goal — drainage stone is meant to stay loosely packed with open gaps so water can move through it freely, unlike a driveway or walkway base, which is compacted specifically to create a dense, stable, load-bearing surface.
How deep should decorative gravel be over a landscape bed?
Typically 1-2 inches over landscape fabric is enough for appearance and light weed suppression — deeper than that mostly adds unnecessary cost without meaningfully improving performance, unlike a structural base where insufficient depth is a real functional problem.
What happens if I order the wrong gravel type for my project?
Using a dense, well-graded base material where an open-graded drainage stone was needed can impede water flow, and using an open-graded drainage stone as a structural base can compact poorly and settle unevenly — the two failure modes are essentially opposite, which is why matching material type (not just depth) to the specific use case matters as much as the volume calculation itself.
How deep should a gravel base be under a shed?
Around 4 inches compacted is a common figure for a small residential shed, though heavier structures or manufacturer-specific kit instructions may call for more — checking the specific structure's requirements is worth doing rather than assuming a driveway or walkway depth automatically applies.
Why does playground gravel need so much more depth than a walkway?
Fall-zone depth requirements are set by impact-attenuation safety standards, not drainage or load-bearing needs — the material needs enough depth to meaningfully cushion a fall from the specific equipment's height, which is an entirely different engineering question from a walkway or driveway base's structural stability.
Does gravel size (not just depth) matter for a driveway base versus a walkway?
Yes — a driveway base commonly uses a larger, angular crushed stone that compacts into a dense, interlocking layer capable of supporting vehicle weight, while a walkway base can often use a somewhat finer material since it only needs to support foot traffic, so matching stone size to the application is worth checking alongside depth.
Should gravel depth be measured before or after compaction?
Order enough loose material to reach your target depth after compaction, not before — compacting a gravel layer typically reduces its loose depth by a meaningful margin, so ordering only enough for the pre-compaction loose measurement usually leaves the finished base thinner than intended.
Is there a project type on this list that commonly gets the wrong depth by default?
Walkway bases are the most common under-built application, since people sometimes assume a thin decorative layer is adequate when a genuine load-bearing base (even for foot traffic) needs real compacted depth to stay stable and not visibly settle within the first year or two of use.