Gravel Calculators

Gravel Driveway Calculator

A driveway built to last is two layers: a thick compacted base of dense-graded stone, plus a thinner top layer of clean stone. This calculator prices nothing — it computes each layer's cubic yards and tons separately, using each layer's own material.

Step 1 · Driveway area
Step 2 · Dimensions
Step 3 · Base layer (typically 4–6" compacted)

Enter 0 to skip this layer (e.g. resurfacing only).

Step 4 · Top layer (typically 2–3" of clean stone)

How the driveway calculation works

Each layer is treated as its own volume problem: driveway area × that layer's depth, converted to cubic yards, then to tons using that layer's material density. The base and top are summed for totals, and the formula line shows both computations.

Worked example — a 20×40 ft two-car driveway: 800 ft² with a 4-inch crusher-run base and 3-inch #57 top. Base: 800 × ⅓ ft = 267 ft³ = 9.9 yd³ ≈ 15.8 tons. Top: 800 × ¼ ft = 200 ft³ = 7.4 yd³ ≈ 10.0 tons. Total ≈ 25.8 tons — call it 27–28 with the standard 5–10% compaction buffer.

Why layers beat one thick fill: a single deep layer of mixed gravel ruts and migrates under traffic. The compacted base carries loads; the clean top drains and finishes. Skipping the separation is the most common — and most expensive — driveway shortcut.

How deep should each layer be?

Typical driveway layer depths by use
Driveway use Base layer Top layer
Light cars only 4" crusher run 2–3" #57 or #67
Cars + occasional trucks 5–6" crusher run 3" #57
Heavy vehicles / soft ground 6–8" (consider #2–3 stone under the base) 3" #57
Resurface only (existing solid base) 0" — skip 2–3" #57

On soft clay or poorly draining ground, geotextile fabric under the base prevents the stone from sinking into the soil over time — cheap insurance compared to redoing the drive. See the gravel types and sizes guide for what each grading code means.

Driveway Cost Calculator

The same two layers priced at your supplier's rates — this page's dollar counterpart.

Paver Base Calculator

Compacted base for paver patios and walkways — a shallower version of the same idea.

Crushed Gravel Calculator

Single-area quantities for crusher run and graded stone.

Gravel Calculator (Tons)

Plain tonnage for any area, with the yards-to-tons density table.

Driveway FAQ

How much gravel do I need for a 2-car driveway?

A typical 20×40 foot two-car driveway (800 sq ft) built properly needs roughly 15–22 cubic yards of gravel depending on layer depths: a 4–6 inch compacted base plus a 2–3 inch top. In tons that's roughly 22–34. Use the calculator above with your actual dimensions for a real number.

Why does a driveway need two layers of gravel?

The base layer (4–6 inches of crusher run or similar dense-graded stone) carries the load and compacts into a stable platform. The top layer (2–3 inches of clean stone like #57) provides the finish surface and drains. One thick layer of mixed material ruts, migrates, and fails faster than the same gravel split into two purpose-built layers.

What's the best gravel for a driveway base?

Crusher run (also called crush and run or dense-graded base) — angular crushed stone with fines that lock together under compaction. For the surface, clean angular stone like #57 or #67 is common. Avoid pea gravel for any driven surface: it's round, rolls under tires, and won't compact.

How much extra gravel should I order?

5–10% over the calculated amount is standard practice, because bases compact by 10–15% and edges always need touch-up material. Many suppliers also deliver in rounded load sizes, so a small buffer usually costs little extra.