Driveway Gravel Calculator
A gravel drive is a road in miniature: layers, compaction, crown, drainage. This calculator prices the layers; the guides below cover the rest.
- 8–12 in
- total depth, new build
- 3
- layers on soft ground
- ~14 t
- per tandem truck load
- 1 in
- surface loss per 2–3 yrs
Driveway Gravel Calculator
Layer-by-layer tonnage for a gravel driveway that lasts — sub-base, base and surface computed separately.
The three-layer system
| Layer | Material & depth | Job |
|---|---|---|
| Sub-base (bottom) | #2 stone (2–3 in rock), 4 in | Bridges soft soil, stops pumpingSkippable on firm ground |
| Base (middle) | #57 stone, 4 in | Structure and drainage |
| Surface (top) | Crusher run, 4 in crowned | Locks tight, sheds waterThe layer you drive on and top up |
Worked example: 200-foot rural drive
A 200 × 12 ft rural driveway on firm ground: standard two-layer build with 10% allowance.
- 1
Area
200 × 12 = 2,400 ft²
- 2
#57 base: 4 in at 109 lb/ft³
2,400 × 0.333 × 109 ÷ 2,000 × 1.10 = 48 tons
- 3
Crusher run surface: 4 in at 140 lb/ft³
2,400 × 0.333 × 140 ÷ 2,000 × 1.10 = 62 tons
- 4
Truckloads
110 ÷ 14 ≈ 8 tandem loads
Result: ≈110 tons across 8 loads — schedule deliveries layer by layer so each gets compacted before the next arrives.
Where driveway gravel estimates fail
Thinking of paving over the gravel later? Build the base layers to this standard and they become the base course for asphalt down the road — nothing is wasted.
Driveway gravel questions
- How much gravel do I need for a 50-foot driveway?
- A 50 × 12 ft drive (600 ft²) as a standard two-layer new build (4 in #57 + 4 in crusher run) needs roughly 24–26 tons with a 10% allowance — two tandem truck loads. A 2-inch resurfacing top-up needs about 6 tons.
- Why order the layers separately?
- Because they're different products doing different jobs: large clean stone bridges soft ground, mid-size stone builds the structure, and fines-rich crusher run locks into the running surface. Suppliers price and load them separately, and mixing them into one order gets you a blend that does neither job.
- Can I skip the sub-base layer?
- On firm, well-drained ground, yes — the two-layer build is standard. The #2 stone sub-base earns its cost on clay, wet ground, or anywhere trucks will use the drive; it's the layer that stops the whole system from sinking. When in doubt, dig a test hole after rain.
- How often does a gravel driveway need topping up?
- Plan on 1 inch of surface material every 2–3 years under regular use — gravel migrates, crushes and presses into the base. That's the top-up option in the calculator. Regular grading (re-crowning) roughly halves the loss rate.
- Gravel vs asphalt driveway — how do costs compare?
- Gravel installs at $1–3/ft² versus $2.50–5 for asphalt, but needs top-ups and grading forever. Gravel wins on long rural drives where asphalt's square footage is brutal; asphalt wins on short suburban drives where its maintenance is minimal. Both cost guides run the numbers.
Plan the whole driveway
Depth, layers, gravel types, cost, installation and maintenance — the complete series.
The driveway series
Related tools & the asphalt path
Sources & references
- [1]Gravel Roads Construction & Maintenance Guide — FHWA / South Dakota LTAP, 2015
- [2]AASHTO M 43: Sizes of Aggregate for Road and Bridge Construction — AASHTO, 2018
- [3]The Aggregates Handbook, 2nd ed. — National Stone, Sand & Gravel Association, 2013