Gravel Depth Guide
A one-page printable reference with the right gravel depth for every outdoor project. Driveways, paths, decorative beds, drainage, and paver bases — each with the recommended gravel type and compaction notes.
What's in the Cheatsheet
The gravel depth guide covers six common project types with the depth range, the right gravel type, compaction factors, and the mistakes that lead to ruts, washouts, or wasted material. It is the reference you check before ordering so you get the depth right the first time.
Recommended Depths by Project
| Project | Depth | Best Gravel Type | Compaction |
|---|---|---|---|
| Driveway (new) | 4–6 in | Crusher run (base) + crushed gravel (surface) | 10% compaction factor |
| Driveway (top-up) | 1.5 in | Crusher run | 10% compaction factor |
| Path / Walkway | 2–3 in | Crushed gravel (angular) | 5% compaction factor |
| Decorative Bed | 2–3 in | Pea gravel or river rock | None (loose fill) |
| French Drain / Trench | 4–12 in | Drainage gravel (#57 style) | None (must stay loose for flow) |
| Paver Base | 4–6 in | Crusher run / DGA | 15% compaction factor |
Why Compaction Factor Matters
When you compact gravel with a plate compactor or roller, it settles and loses volume. If your finished depth needs to be 4 inches, you must start with more than 4 inches of loose material. Crusher run with fines compacts about 10–15%, meaning you should order that much extra. Clean decorative gravel like pea gravel does not compact significantly because the round particles do not lock together. The cheatsheet includes a compaction multiplier for each project type so your order accounts for the settlement.
Gravel Type Selection
Angular gravel (crusher run, crushed gravel) interlocks when compacted, making it ideal for driveways, bases, and paths where stability matters. Round gravel (pea gravel, river rock) rolls underfoot and does not compact, making it better for decorative beds where you want easy raking and a clean look. For drainage, the key requirement is "clean" gravel with no fines. Fines clog drain pipe and geotextile fabric, defeating the purpose of the trench. The cheatsheet maps every project to the right gravel profile so you do not get the wrong one.
Driveway Layer System
A properly built gravel driveway has at least two layers. The bottom layer is 3–4 inches of crusher run (dense-graded aggregate with fines) that compacts into a solid base. The top layer is 2–3 inches of angular crushed gravel that provides the finished driving surface. Putting pea gravel on a driveway is a common and expensive mistake: round gravel does not compact, creates ruts under tires, and migrates off the edges within a season. The depth guide highlights this layering system with specific depths for each layer.
Calculate Your Order
Once you have your depth from this guide, plug your project dimensions into the Gravel Calculator to get exact quantities in cubic yards, tons, and bags. The calculator applies your compaction factor and waste percentage automatically and shows purchase formats from 50-lb bags to full truckloads.