Gravel Calculator Formula

Understand the math behind the gravel calculator. Each variable explained with a worked example.

Use the Gravel Calculator

Formulas Used

Volume (Cubic Feet)

cubic_feet = length * width * depth_ft

Volume (Cubic Yards)

cubic_yards = length * width * depth_ft / 27

Weight (Tons)

tons = length * width * depth_ft / 27 * 1.4

Variables

VariableDescriptionDefault
lengthLength(feet)30
widthWidth(feet)10
depthDepth(inches)3
depth_ftDerived value= depth / 12calculated

How It Works

How to Calculate Gravel Needed

Formula

Cubic Yards = (Length × Width × Depth in feet) / 27

Tons = Cubic Yards × 1.4

Gravel weighs approximately 2,800 lbs (1.4 tons) per cubic yard. This can vary from 1.3 to 1.5 tons depending on the type and moisture content.

Worked Example

A driveway 30 ft long, 10 ft wide, with 3 inches of gravel.

length = 30width = 10depth = 3
  1. 01Depth in feet: 3 / 12 = 0.25 ft
  2. 02Volume = 30 × 10 × 0.25 = 75 cu ft
  3. 03Cubic yards = 75 / 27 = 2.78 cu yd
  4. 04Tons = 2.78 × 1.4 = 3.89 tons

Ready to run the numbers?

Open Gravel Calculator