Gravel Driveway Calculator
Most tools treat a driveway as one slab of stone. It isn’t. It’s three grades at three depths, each with its own density and its own price, so this gravel driveway calculator sizes every course separately and tells you what to order from the quarry line by line.
Your result
| Layer | Grade | Depth | Tons | Cost |
|---|---|---|---|---|
| Base course | #3 or #4 crushed stone | 4" | 22.4 | $672 |
| Middle course | #57 stone | 4" | 23.9 | $906 |
| Top course | Crusher run or #411 | 4" | 26.7 | $853 |
| Total | 12" | 72.9 | $2,432 |
What to order
22.4 tons #3 or #4 crushed stone + 23.9 tons #57 stone + 26.7 tons Crusher run or #411 — 72.9 tons total
$2,432 of material, or $2.03 a square foot before delivery and labor. That is 6 tandem dump loads at 14 tons each.
- Why three layers and not one
- Each course does a different job. large angular stone that bridges soft ground and carries the load; the middle locks into it and drains; the top packs down into something you can drive on. Pour 12 in of a single grade instead and it either drains badly or never firms up, depending which grade you picked.
- Compaction is already included
- base course 12%, middle course 15%, top course 20%. The depths you entered are finished depths, so the tonnage above is the loose material you buy to end up with them.
- Why this is not sold in bags
- This job is 2,776 half cubic foot bags. Bagged gravel makes sense for a pothole and nothing larger, which is why driveway gravel is quoted by the ton and delivered loose.
- How this is worked out
- Base course: 1,200 sq ft × 4 in ÷ 12 ÷ 27 = 14.81 cu yd, + 12% = 16.59 cu yd × 2,700 lb ÷ 2,000 = 22.4 tonsMiddle course: 1,200 sq ft × 4 in ÷ 12 ÷ 27 = 14.81 cu yd, + 15% = 17.04 cu yd × 2,800 lb ÷ 2,000 = 23.85 tonsTop course: 1,200 sq ft × 4 in ÷ 12 ÷ 27 = 14.81 cu yd, + 20% = 17.78 cu yd × 3,000 lb ÷ 2,000 = 26.67 tons
Calculate driveway gravel one layer at a time
Work out the area once, then run it through the depth of each course separately. Length times width gives square feet. Multiply by the layer depth in inches, divide by 12 for cubic feet and by 27 for cubic yards, add that layer’s compaction allowance, then convert to tons using that grade’s own weight per yard.
The reason it has to be done per layer is that the three grades are not interchangeable numbers. Base stone runs 2,700 lb a cubic yard, #57 about 2,800 and crusher run 3,000, and they settle 12%, 15% and 20% respectively. Use one average figure for all three and you can be several tons out on a long drive, which on a per-load delivery is a real cost rather than a rounding error.
A 100 by 12 ft drive is 1,200 sq ft. Built in three 4 in courses it needs 22.4 tons of base, 23.9 of #57 and 26.7 of crusher run, which is 72.9 tons and about 51.4 cubic yards altogether. That is 6 tandem loads, and the second-to-last one is the one worth checking before you order.
Layers of a gravel driveway, and what each one does
A driveway is built like a road in miniature. The bottom layer carries the load, the middle layer locks the structure together and drains it, and the top layer is the only one you actually see or drive on. Skip any of the three and the failure shows up somewhere predictable.
| Course | Grade | Depth | Weight per yd³ | What it does |
|---|---|---|---|---|
| Base course | #3 or #4 crushed stone | 4" | 2,700 lb | Large angular stone that bridges soft ground and carries the load |
| Middle course | #57 stone | 4" | 2,800 lb | Golf-ball sized clean stone that locks into the base and drains |
| Top course | Crusher run or #411 | 4" | 3,000 lb | Stone dust and chip that packs into a firm driving surface |
Read the grade column and the logic is that stone gets smaller as you go up. Large angular rock at the bottom bridges soft ground the way a snowshoe spreads weight. Mid-sized clean stone above it keys into the gaps without filling them, so water still gets through. Fines only appear in the top course, where they bind the surface into something a car won’t throw out from under its tires.
Put crusher run straight onto soil and the fines wick up moisture and turn the whole thing to mud. Put #57 on top with nothing binding it and it stays loose and migrates to the edges. The order matters as much as the quantity, which is why the calculator prices them as three separate deliveries.
How deep should a gravel driveway be?
Eight to twelve inches of total build-up on bare ground, and two to three inches of fresh stone when resurfacing something already compacted. The standard split is 4 in per course across three courses, which lands at 12 in total.
| Situation | Total depth | How to split it |
|---|---|---|
| Resurfacing a firm drive | 2–3" | Top course only |
| New drive, firm dry subgrade | 8" | 4" base, 4" top |
| New drive, normal soil | 12" | 4" base, 4" middle, 4" top |
| Clay, wet ground or heavy vehicles | 14–18" | 6–8" base, 4" middle, 4" top, over fabric |
The figure that catches people out is the bottom row. Going from 12 to 18 in of build-up is half as much stone again, and that’s exactly the situation where skimping guarantees you pay twice. Wet clay swallows base rock, so either the depth goes up or geotextile goes down, and fabric is far cheaper than another six inches of stone.
Depth is measured after compaction, which is why every figure here is bigger by the time it leaves the quarry. It also has to be built in lifts. Dumping 12 in of stone and running a compactor over it once compacts the top few inches and leaves the rest loose, so each course goes down, gets levelled and gets compacted before the next one arrives.
Tons vs cubic yards: which one your supplier quotes
Quarries sell gravel by the ton and load it by the cubic yard, so both units come up in the same phone call. A cubic yard of driveway stone weighs between 2,700 and 3,000 lb depending on the grade, which puts it between 1.35 and 1.5 tons per yard.
| Grade | Lb per cubic yard | Tons per cubic yard | Cubic yards per ton |
|---|---|---|---|
| #3 or #4 crushed stone | 2,700 | 1.35 | 0.74 |
| #57 stone | 2,800 | 1.4 | 0.71 |
| Crusher run or #411 | 3,000 | 1.5 | 0.67 |
The practical rule is that a cubic yard of any driveway grade is about a ton and a half, so multiply yards by 1.5 for a quick tonnage check. That is close enough to catch an order that is wildly wrong and not close enough to order from, which is the distinction that matters when a supplier reads a number back to you.
Where it goes wrong is comparing quotes in different units. A yard priced against a ton looks a third cheaper than it is. Ask which unit the price refers to before comparing two suppliers, because the gap between them is usually smaller than the unit confusion makes it look.
Common driveway sizes and what they take
Width is the number people get wrong. A single lane needs 10 to 12 ft to let a car door open clear of the grass, and anything narrower means the edges break down within a couple of years as tires run off them.
| Driveway | Size | Area | Tons | Material cost |
|---|---|---|---|---|
| Single car | 20 × 10 ft | 200 sq ft | 12.2 | $405 |
| Double car | 20 × 20 ft | 400 sq ft | 24.3 | $811 |
| 50 ft drive | 50 × 12 ft | 600 sq ft | 36.5 | $1,216 |
| 100 ft drive | 100 × 12 ft | 1,200 sq ft | 72.9 | $2,432 |
| 300 ft rural | 300 × 12 ft | 3,600 sq ft | 218.8 | $7,295 |
The jump from a 20 by 10 ft parking pad at 12.2 tons to a 300 ft rural drive is the reason these jobs are hard to budget by instinct. Tonnage scales exactly with area, so doubling the length doubles the stone, but delivery does not scale the same way and neither does the machine time to spread it.
Add a turnaround or parking apron as a separate area rather than lengthening the drive to account for it. A modest turnaround is 20 by 20 ft, which on its own is close to the whole material bill for a single-car pad, and it is the item most often left out of a first estimate.
Which gravel grade to order for each layer
Grade numbers describe the size of the screened stone, and they are not interchangeable between layers. The three that matter for a driveway are large angular base rock, #57 clean stone and crusher run.
Base course
#3 or #4 crushed stone, sometimes sold as bull rock, rip-rap or simply base rock. Pieces run 1 to 2 in and interlock into a rigid mat. It is the cheapest of the three at around $30 a ton and the one most often skipped, which is also the single most common reason a drive fails early.
Middle course
#57 stone, roughly 3/4 in and washed clean of fines. It keys down into the base and leaves enough void space that water drains through rather than sitting under the surface. At about $38 a ton it is usually the dearest layer, and on a firm dry subgrade it is the one you can leave out.
Top course
Crusher run, also sold as #411, CR-6, road base or dense grade. It is crushed stone with the dust left in, so it packs down hard and sheds water rather than letting it through. Nothing else makes a good driving surface, and pea gravel in particular is a poor choice here because rounded stone never locks together and simply rolls under tires.
Driveway gravel cost per ton and per square foot
Material for a full three-layer build works out at about $2.03 a square foot, or roughly $2,432 for a 100 by 12 ft drive. Per ton, base stone is near $30, #57 around $38 and crusher run about $32, all delivered within a normal radius.
| Layer | Tons | Per ton | Cost |
|---|---|---|---|
| Base course | 22.4 | $30 | $672 |
| Middle course | 23.9 | $38 | $906 |
| Top course | 26.7 | $32 | $853 |
| Total | 72.9 | — | $2,432 |
Delivery is the line that surprises people. Haulage runs $75 to $150 a load and this drive is 6 tandem loads, so getting it to site can add most of another thousand dollars on top of the stone. It’s charged per trip regardless of how full the truck is, which is why ordering a few tons over a load boundary is worth avoiding.
Installed by a contractor, a new drive of this size typically lands between $2,000 and $6,000 including excavation, grading and compaction. Resurfacing is far cheaper: 2 in of fresh crusher run over the same drive is about 13.3 tons, or roughly $427 in material, which is why topping up every few years beats letting a drive fail and rebuilding it.
Gravel driveway questions
How much gravel do I need for my driveway?
Multiply length by width for square feet, then work out each layer on its own. A 100 by 12 ft drive built in three 4 in courses needs about 73 tons in total, or roughly 51 cubic yards loose. Sizing it as one 12 in slab of a single grade gets both the tonnage and the grade wrong.
How much does it cost to gravel a driveway?
Material for a full three-layer build runs about $2.03 a square foot. That 100 by 12 ft drive comes to roughly $2,432 in stone before delivery and labor. Installed by a contractor, expect $2,000 to $6,000 for the same drive depending on ground conditions and access.
How thick should a gravel driveway be?
Between 8 and 12 in of total build-up on bare ground, split across three courses of 4 in each. Resurfacing an existing compacted drive only needs 2 to 3 in of fresh top course. Anything under 6 in total on soil will rut in the first wet season.
How much gravel for 100 ft driveway?
At the usual 12 ft width that is 1,200 sq ft. A new build in three 4 in layers takes about 22 tons of base stone, 24 tons of #57 and 27 tons of crusher run. Resurfacing the same drive with 2 in of top course takes about 13 tons.
How much does a 100 ft gravel driveway cost?
Around $2,432 in material for a full build, or about $427 to resurface it with 2 in of crusher run. Delivery adds $75 to $150 a load and this job is 6 tandem loads, so haulage alone can add several hundred dollars.
What is the base layer for a gravel driveway?
#3 or #4 crushed stone, laid 4 in deep straight onto compacted subgrade. It is large angular rock, typically 1 to 2 in, that bridges soft spots and spreads vehicle load. Smaller stone put down first sinks into the soil and disappears within a year.
How much is a load of gravel for a driveway?
A tandem dump carries about 14 tons, which at $32 a ton for crusher run is roughly $448 of stone plus $75 to $150 haulage. Because delivery is charged per trip, ordering 15 tons costs a whole extra load.
How much does driveway gravel cost per ton?
Base stone runs about $30 a ton, #57 around $38 and crusher run near $32, all delivered. Prices swing widely by region because stone is heavy and travels badly, so a quarry 20 miles away often beats one 60 miles away by more than the rate suggests.
Can I put new gravel over old gravel?
Yes, provided the old surface is still firm and drains. Grade out the ruts first, then add 2 to 3 in of fresh top course and compact it. If the drive has soft spots that move underfoot, the problem is the base and adding stone on top will not fix it.
Do I need fabric under a gravel driveway?
On clay or anywhere the ground stays wet, yes. Geotextile stops the base stone from being pushed down into the soil, which is the usual reason a driveway needs topping up every year. On firm, well drained subgrade it is optional.