Crushed Stone Sizes Explained
The number on crushed stone (#1, #3, #57, #8…) tells you the size range of the stones — and the size decides what the product is for. Order the wrong grade and a driveway stays muddy, a French drain clogs, or a paver patio heaves. This chart translates supplier jargon into plain English so you can order like a contractor.
| Grade | Stone size | Typical uses |
|---|---|---|
| #1 | 2–4 in | Culvert protection, erosion control, very soft-ground stabilization. Too coarse to walk on comfortably. |
| #3 | 1–2 in | Driveway and road sub-base, drainage behind retaining walls, muddy-area rescue. |
| #57 | ¾–1 in | The all-rounder: driveway middle layer, concrete slab base, French drains, walkway base. |
| #8 | ⅜–½ in | Pipe and paver bedding, asphalt mixes, decorative topping over #57. |
| #10 (screenings) | Dust–⅛ in | Final leveling bed under pavers, filling joints, under horse arenas. |
| Crusher run / #411 | ¾ in minus incl. fines | Compactable surface layer for driveways and paths; packs almost like soft concrete. |
| Pea gravel | ⅜ in, rounded | Decorative beds, playgrounds, dog runs — NOT driveways; round stones never lock together. |
The two families: clean stone vs. minus products
Every crushed product falls into one of two families, and mixing them up is the most common ordering mistake:
- Clean (washed) stone — single-size angular rock with the dust screened out. It stays permanently loose and free-draining. That's what you want in French drains, behind retaining walls, and under slabs: water passes straight through.
- Minus products (crusher run, #411, "road base") — stone plus all the crushing fines. Compacted in 2–3 inch lifts, the fines bind the mass into a hard, almost pavement-like surface. That's what you want as the top of a gravel driveway or path — but never in a drain, where the fines wash out and clog everything downstream.
Crushed stone vs. gravel vs. pea gravel
Suppliers use "gravel" loosely, but the distinction matters. Crushed stone is quarried rock run through a crusher — angular faces that lock together under compaction. Natural gravel and pea gravel are river-worn and rounded — they roll against each other forever, which makes them comfortable underfoot in a play area and useless as a driving surface. If wheels or foundations are involved, insist on crushed, angular material.
Ordering the right amount
Suppliers sell by the cubic yard or by the ton (crushed stone runs about 1.4 tons per cubic yard). Measure your area, pick the depth for the job — 2–3 inches for a top-up, 4 inches for a base layer — and let the gravel calculator convert it to yards and tons. Building a full driveway? The gravel driveway guide walks through all three layers and their depths.
Frequently asked questions
What is the best gravel size for a driveway?
For the driving surface, crusher run (¾-inch minus with fines) compacts hardest and drives smoothest. #57 works as a surface too and drains better, but stays slightly loose underfoot. Use #3 underneath as the load-bearing base.
What does the "minus" in ¾-inch minus mean?
It means the product contains everything from ¾-inch stones down to rock dust (fines). The fines fill the voids and let the material compact into a dense, firm mass. "Clean" or washed stone has the fines screened out, so it stays loose and free-draining.
Which stone should I use under a concrete slab?
#57 clean stone is the most common choice: it compacts adequately, drains freely, and creates a stable, uniform bearing surface. Typical depth is 4 inches under patios and 4–8 inches under driveways.
How much does a ton of crushed stone cover?
At 2 inches deep, one ton of typical crushed stone covers roughly 100 square feet. Halve that for a 4-inch depth. Density varies a little by rock type, which is why our calculator lets you pick the material.
Last reviewed on 2026-07-17. Grade numbers follow the common US quarry convention (based on AASHTO size designations); exact ranges and local names — "57s", "clean rock", "road base" — vary by region, so describe the job to your supplier when in doubt.