Road Base Calculator
Cubic yards and tons of road base, Class 5 or crusher run for driveways and paver sub-bases.
Quick estimating rule of thumb
For road base: length (ft) × width (ft) × depth (in) ÷ 324 = cubic yards. Class 5 / crusher run is about 1.5 tons per yard and is built 4 to 6 inches thick for a driveway. It compactes hard, so order 15% extra if you are plating it in layers.
This road base calculator converts an area and depth into the cubic yards and tons of road base (also sold as Class 5, crusher run, dense-graded aggregate, or #411) that you need for a driveway, a paver or slab sub-base, or a shed pad.
Road base is a graded mix of crushed stone and fines that compacts to a hard, load-bearing layer. It is ordered loose and reduces by about a quarter under compaction; the tool adds a 10% allowance on top.
How deep should road base be?
Under pavers: 4 inches compacted for patios and walkways, 6 inches for driveways, over a compacted sub-grade. Under a concrete slab: 4 inches. For a gravel driveway base: 4 to 6 inches, then a surface course of angular stone. Always compact in 2-inch lifts, wetting each lift lightly. Dry material will not knit together.
One ton of road base covers roughly 90 square feet at 2 inches compacted, or 45 square feet at 4 inches.
Sub-grade first
Road base only performs over a firm, compacted sub-grade. Strip topsoil and soft spots, compact the exposed soil, and lay a woven geotextile over clay or anywhere the ground stays wet. It stops the base from pumping down into the soil and rutting.
Ordering
Road base is sold by the ton; a cubic yard weighs about 1.5 tons. Order for the loose depth (roughly a third more material than the compacted volume), plus 10% waste. A tandem truck carries 15 to 20 tons.
Common road-base mistakes
Compacting dry. Road base needs a little water to knit. Sprinkle each lift before the plate compactor.
Thick lifts. Compact in 2-inch layers; a 4-inch lift stays loose in the middle.
Skipping the sub-grade prep. Strip topsoil and soft spots and compact the exposed soil first, or the base settles unevenly.
Ordering compacted volume. Order for the loose depth, about a third more.
| Material | lb / ft³ | tons / yd³ | Sold by | Typical use |
|---|---|---|---|---|
| Pea gravel (3/8″, rounded) | 100–105 | 1.35 | ton or yd³ | Paths, patios, dog runs, drainage |
| #57 crushed stone (3/4″, washed) | 100–105 | 1.35 | ton | Drainage, slab sub-base, French drains |
| 3/4″ minus / dense-grade | 105–115 | 1.45 | ton | Driveway base, paver base, road pack |
| Crushed concrete (RCA) | 100–110 | 1.35 | ton | Driveway base, structural fill (cheaper) |
| River rock (1–3″) | 95–105 | 1.40 | ton or yd³ | Dry creek beds, borders, xeriscape |
| Decomposed granite | 110–120 | 1.50 | ton | Paths, patios, natural-look driveways |
| Road base / Class 5 | 110–120 | 1.50 | ton | Compacted base under pavers, slabs, drives |
Background reading: how much a yard of gravel weighs, cubic yards to tons chart and gravel cost per ton and per yard.
Frequently asked questions
How much road base do I need?
Work out the compacted volume (area × depth ÷ 27), add about a third for compaction, then 10% for waste. A 400 square foot driveway at 4 inches compacted needs roughly 8 to 9 tons.
How many tons of road base in a cubic yard?
About 1.5 tons, because the fine content makes it denser than clean crushed stone.
How deep should road base be under pavers?
Four inches compacted for pedestrian areas, six inches for driveways, laid and compacted in 2-inch lifts.
What is the difference between road base and crushed stone?
Road base is a dense-graded mix with crushed fines that compacts to a hard surface. Clean crushed stone (like #57) has the fines removed and stays loose for drainage.
Is Class 5 the same as road base?
Effectively yes. Class 5 is the Minnesota/upper-Midwest name for a dense-graded aggregate base. Crusher run, DGA, and #411 are regional equivalents.
How much area does a ton of road base cover?
About 90 square feet at 2 inches compacted, 60 at 3 inches, and 45 at 4 inches.
Do I need fabric under road base?
Over clay, silt or persistently wet ground, yes. A woven geotextile keeps the base and the sub-grade from mixing. Over firm, well-drained soil it is optional.
Can you compact road base by hand?
Only small areas, poorly. Rent a plate compactor for anything larger than a few square feet, and a jumping jack for trenches.
How many tons of road base for a 500 square foot driveway?
At 4 inches compacted, about 8 to 9 tons after the compaction and waste allowance.
Is road base the same as crusher run?
Effectively yes. Crusher run, dense-graded aggregate (DGA), Class 5, #411 and "road base" are regional names for the same graded crushed stone with fines.
Can I use road base as a final driveway surface?
It works as a hard-packed surface, but a 1 to 2 inch top course of clean angular stone drains better and looks finished. Re-grade the base every year or two.
How deep should road base be under a concrete slab?
Four inches compacted over a firm sub-grade is standard for residential slabs.
Do I need fabric under road base?
Over clay, silt or wet ground, yes. A woven geotextile stops the base and sub-grade from mixing. Over firm dry soil it is optional.