Class 6 gravel is the stricter, cleaner grade: fewer fines, more crushed stone, tighter quality rules. Class 5 is the common workhorse that suits most driveways and bases. For a typical residential driveway, either one works if it is spread in compacted lifts over a drained subgrade. The better choice depends on your soil, your traffic and what your local yard actually sells under those names.
One warning first. "Class 5" and "Class 6" are state and agency specifications, not universal products. The names you see online mostly come from Minnesota's DOT, and a yard in Cincinnati may sell something with a different name that does the same job. This guide explains what the classes mean, how they differ, what they cost, and how to get a driveway that lasts.
TL;DR
- Class 6 has fewer fines, more crushed material and stricter aggregate requirements than Class 5, so it is generally regarded as the higher-quality grade.
- Class 5 is the most commonly used base and fits most situations, driveways included.
- Neither is a drainage stone. Both drain better than native soil but far worse than open-graded rock.
- Specifications differ by state and city, so describe the gradation you want and let the local yard match it.
- Compaction, crown and drainage decide whether a driveway lasts, more than the class number does.
Table of Contents
- What "Class 5" and "Class 6" actually mean
- How Class 5 and Class 6 differ
- Which one fits which job
- What it costs
- Getting the installation right
- Our perspective
- Need the driveway fixed, not just explained?
- Frequently asked questions
- Sources
What "Class 5" and "Class 6" actually mean
Both names describe dense-graded aggregate base: a blend of stone sizes from coarse down to fine dust, designed to pack tightly when damp and compacted. The most-cited definitions come from the Minnesota Department of Transportation, and a guide to these spec gravels points to its Specification 3138 as the best-known source.
Cities and counties write their own versions. In Pueblo, Colorado, the city's aggregate base specification calls for Class 6 to be 100% passing the ¾-inch sieve, while Class 5 is 100% passing the 1½-inch sieve. So in that spec, Class 6 is simply the smaller top-size stone. In Minnesota's system the difference is mostly about fines and crushing. Same names, different recipes.
The same kind of material also travels under many other names. A regional trade-name list shows that crusher run, CA-6 and 21-A can all describe comparable structural aggregate depending on where you stand.
Why this matters when you order
If a plan, a neighbor or a website says "Class 5" and you live in the Ohio, Kentucky or Indiana tri-state area, do not assume the local yard has a product by that exact name. Describe the job: dense-graded crushed base, top size around one inch, with fines for binding. Then ask the yard which of its products matches. Our related guide on questions to ask a supplier about crushed stone vs gravel lists what to ask.
How Class 5 and Class 6 differ
Here is the practical comparison, based on MnDOT's definitions. The agency's pavement design chapter says Class 6 is generally regarded as somewhat higher quality than Class 5, with fewer fines, more crushed material and stricter aggregate-property requirements.
| Factor | Class 5 | Class 6 |
|---|---|---|
| Fines (dust and small particles) | More | Fewer |
| Crushed content | Less | More |
| Quality requirements | Standard | Stricter |
| Typical use | Most base situations | Higher-demand bases |
| Drainage | Limited | Limited, slightly better with fewer fines |
| Price | Generally lower | Often a bit higher, varies by yard |
Two things stand out. First, the gap is a matter of degree. Class 6 is a tightened version of the same idea, not a different kind of rock. Second, the "limited drainage" row is the same for both. MnDOT's guidance is that Class 5 and Class 6 bases drain better than non-granular native soils but have limited drainage compared with open-graded drainage materials.
What fines do
Fines are the dust and small particles in the mix. They are what lets a base lock together. Dense-graded base compacts properly when damp: smaller sizes fill the voids between larger stones, and water plus compaction produces an interlocked mass.
Too many fines and the surface turns slick and muddy when it stays wet. Too few and the surface stays loose and ravels under tires. Class 6's lower fines content leans toward the second risk but gives a cleaner, more durable crushed structure. Class 5's extra fines bind easily but hold more water.
Which one fits which job
MnDOT says Class 5 is the most commonly used base and applicable in most situations. Both classes serve as aggregate base beneath asphalt or concrete pavement. For a homeowner, that translates into a simple rule set.
Choose Class 5 when
- You have a standard residential driveway with passenger vehicles and the occasional delivery.
- Your subgrade is reasonably firm and water leaves the site.
- You want the widely available, usually cheaper option.
- You are building a base under pavers, a shed pad or a walkway.
Consider Class 6 when
- The drive carries heavier or more frequent loads, such as trucks, trailers or farm equipment.
- Wet seasons keep the area damp and you want less dust-driven mud.
- A plan or local specification calls for it.
- You want a cleaner crushed surface and the price difference is small.
When neither is the right answer
If water sits on or under your driveway, a different class will not fix it. Both are dense-graded and hold moisture, so standing water needs grading, ditches or a drainage layer first. Our guide to a muddy gravel driveway explains why adding more gravel on top of a wet problem fails, and the drainage and 18 inch rule article covers what to do instead. Steep lots have their own issues, covered in gravel driveways on a slope.
What it costs
Prices swing with your distance from the quarry, the quantity and the delivery fee. One national cost guide puts Class 5 sand and gravel mix at $11 to $19 per ton, or $15 to $25 per cubic yard, and road base more broadly at $18 to $30 per ton. The same guide notes that one cubic yard holds roughly 1.4 to 1.5 tons of stone and that small quantities can run above $100 per ton.
Those are national averages, not tri-state quotes. Treat them as a sanity check and ask local yards for delivered prices, since trucking often costs as much as the stone on a small order. I could not find a reliable published price spread between Class 5 and Class 6 specifically, so ask your yard to quote the closest matching products side by side.
For a full installed-cost view, including the labor and base layers, see our gravel driveway installation cost breakdown.
Getting the installation right
The material matters less than the method. Highway agencies that maintain thousands of miles of gravel roads keep returning to the same basics. The Local Highway Technical Assistance Council's gravel roads manual describes scarifying the existing surface, re-establishing the crown, fixing poor drainage, and adding moisture as needed before final spreading and compaction.
Plan for shrinkage
The same manual gives a rule of thumb: loose material shrinks by about 25 to 30% once spread and compacted. If you want four inches of finished base, order enough to spread roughly five and a half to six inches loose. Our driveway thickness guide shows how deep each layer should be.
Compact in lifts
Spread in layers, wet the material lightly and compact each lift. Dumping a deep pile and running over it with a truck leaves soft pockets that rut within a season. Practical placement and compaction advice for stable bases also appears in this write-up on gravel under pavers and 3 to 4 inch lifts, which applies the same lift logic to patios.
Add fabric and edges where they earn their keep
On soft or clay soils, a separation fabric keeps the base from sinking into the subgrade. See our guide to driveway geotextile fabric. Edges keep stone from migrating onto the lawn, and a compacted base is what makes them work, as explained in driveway edging options.
Maintain it
Raking, refilling low spots and clearing ditches each year beats a full rebuild every few years. Our drainage-first maintenance steps fit into a weekend.
Our perspective
We repair and build gravel driveways around Cincinnati, and the class number is rarely what we see fail. We see driveways that were topped up again and again over soft ground, with no crown and a ditch full of leaves. New stone on top of water just becomes mud with a better price tag.
Our advice is to choose the material for the job, then spend your effort on the base. A firm subgrade, a crowned surface, water with somewhere to go and compaction in lifts will make Class 5 outperform a carelessly placed Class 6. When a drive carries heavy loads or stays wet for long stretches, a stricter, cleaner crushed grade is worth the small premium.
It also helps that we handle the clearing as well as the stone. Overgrown edges, stumps and brush that shade the drive and keep it damp are often part of why it stays wet. We grind and mulch that vegetation on site in one pass, with no burning or hauling, then regrade and rebuild the surface.
— Yoshua
Need the driveway fixed, not just explained?
If you would rather have a crew assess the drainage, clear the edges and place the right base, our team handles gravel driveway repair and installation in Cincinnati. We also clear the brush, saplings and stumps that crowd a driveway, and you can get a number quickly with our instant pricing calculator.
We serve the Ohio, Kentucky and Indiana tri-state area, and flexible financing is available for larger jobs. Browse everything we do on our services page.
Frequently asked questions
Is Class 6 gravel better than Class 5?
Class 6 is generally regarded as higher quality because it has fewer fines, more crushed material and stricter aggregate requirements. "Better" depends on the job, though. Class 5 is the most commonly used base and suits most residential situations when it is properly compacted over a drained subgrade.
Can I use Class 5 or Class 6 for drainage?
No. Both are dense-graded and offer limited drainage compared with open-graded drainage stone. They drain better than native clay or silt, but standing water needs grading, ditches or a dedicated drainage layer.
Will my local yard sell Class 5 and Class 6?
Maybe not under those names. These are agency specifications, and other regions sell similar material as crusher run, CA-6 or other local names. Describe the gradation and top size you need and ask the yard which product matches.
How much gravel should I order?
Order for compacted depth plus shrinkage. Loose gravel typically compacts by about 25 to 30%, so a four-inch finished layer needs noticeably more than four inches loose. One cubic yard is roughly 1.4 to 1.5 tons.
Sources
- MnDOT pavement design chapter on aggregate bases
- City of Pueblo, Article 6, Aggregate Base Course
- Road Base, Class 5 and CR6: Spec Gravels Explained
- Gravel and Aggregate Trade Names by State
- How Much Does Crushed Stone or Gravel Cost?
- LHTAC Gravel Roads Manual (2021)