How Many Bags of Gravel Do I Need?

Overview

Bag sizes, coverage and how to convert a bulk cubic-yard figure into bagged quantities.

Use the gravel calculator on the homepage to get an instant estimate, then read on for the details.

The core formula

The volume of gravel you need comes from three measurements, length, width and depth:

1. Measure length and width in feet, and depth in inches.
2. Convert depth to feet (divide inches by 12).
3. Multiply the three together for cubic feet.
4. Divide by 27 to get cubic yards.

Example: a 20 ft × 10 ft area at 4 inches deep = 20 × 10 × 0.333 = 66.7 ft³ ÷ 27 ≈ 2.5 cubic yards.

Converting to tons and bags

Gravel weighs roughly 1.4 tons per cubic yard, so multiply your cubic yards by 1.4 for tonnage. For bagged gravel, a standard 0.5 ft³ bag means one cubic yard is about 54 bags.

Tips before you order

• Add 5–10% for compaction and spillage.
• Order slightly more for driveways that carry vehicle weight.
• Check your supplier’s density, decorative stone can be lighter or heavier than the 1.4 t/yd³ rule of thumb.

Ready to crunch your own numbers? Head back to the calculator and enter your measurements.