How much gravel do I need for a driveway?

Measure the length, width, and desired depth of your driveway. Multiply the three dimensions (with depth converted to feet) to get cubic feet, then divide by 27 for cubic yards. For example, a 40 × 12 ft driveway at 4 inches deep needs about 5.93 cubic yards.

How deep should driveway gravel be?

A residential gravel driveway typically needs 4 to 6 inches of compacted depth. A two-layer approach — a base of coarse gravel topped with a finer surface layer — provides better durability.

How do I calculate cubic yards of gravel?

Calculate the volume in cubic feet (Length × Width × Depth in feet), then divide by 27. One cubic yard equals 27 cubic feet.

How do I convert cubic feet to cubic yards?

Divide the number of cubic feet by 27. Since one cubic yard is 3 × 3 × 3 = 27 cubic feet, this conversion gives you the volume in the unit most suppliers use.

Should I add extra gravel?

Yes. Gravel compacts and settles, so ordering 10–15% more than the calculated volume is a good practice. It is also useful to have spare material for future top-ups and patching.

Guide

How to Calculate Gravel for a Driveway

A durable gravel driveway starts with the right quantity of material. Order too little and you end up with thin, patchy coverage; order too much and you pay for material you do not need. This guide covers the formula, a worked example, and practical tips so you can estimate with confidence.

Key Takeaways

Gravel volume is calculated as Length × Width × Depth.
Convert depth from inches to feet before multiplying.
Divide cubic feet by 27 to get cubic yards — the standard unit for bulk gravel.
Gravel depth typically ranges from 4 to 6 inches for residential driveways.
Use the NOVORY Gravel Calculator for an instant estimate.

Calculate Gravel

How to Calculate Gravel Volume

The process is the same as any volume calculation: multiply the three dimensions together. The important part is getting all measurements into feet before you multiply.

1Measure the length and width of the driveway in feet.
2Decide on the gravel depth — typically 4 to 6 inches for a residential driveway.
3Convert depth from inches to feet by dividing by 12.
4Multiply Length × Width × Depth (in feet) to get cubic feet.
5Divide by 27 to convert cubic feet to cubic yards.

The Gravel Volume Formula

For a rectangular driveway area, the formula is:

Volume (cu ft) = Length (ft) × Width (ft) × Depth (ft)

Worked Example: 40 ft × 12 ft Driveway at 4 Inches Deep

Say your driveway is 40 feet long, 12 feet wide, and you want 4 inches of gravel depth. Here is the step-by-step calculation.

Step 1

Measure the driveway: 40 ft long × 12 ft wide, 4 inches deep.

Step 2

Convert depth to feet: 4 ÷ 12 = 0.333 ft.

Step 3

Calculate cubic feet: 40 × 12 × 0.333 ≈ 160 cubic feet.

Step 4

Convert to cubic yards: 160 ÷ 27 ≈ 5.93 cubic yards.

Common Mistakes

Forgetting to convert depth from inches to feet — this inflates the volume by 12×.
Using a single layer of gravel that is too thin — a driveway needs a compacted base layer plus a surface layer.
Ignoring compaction — gravel settles and compacts, so you may need 10–15% more than the calculated volume.
Not accounting for slope or crown — sloped driveways may require more material on the sides for proper drainage.
Confusing cubic yards with tons — gravel weight per cubic yard varies by material type and moisture content.

Practical Tips

For a two-layer driveway, use larger gravel (3/4 inch minus) for the base and smaller gravel (5/8 inch minus) for the top layer.
Ask your supplier for the weight per cubic yard of the specific gravel type you are ordering to convert volume to tons.
If the driveway has curves or irregular shapes, break it into rectangles and calculate each section separately.
Consider ordering 10–15% extra to account for compaction and settling over time.
Use the NOVORY Gravel Calculator to double-check your estimate.