Gravel Bed Calculator Formula

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

Use the Gravel Bed Calculator

Formulas Used

Gravel Volume

cubic_yards = vol_cuft / 27

Approximate Weight

tons = vol_cuft / 27 * 1.4

Bed Area

area = length * width

Variables

Variable	Description	Default
`length`	Length(ft)	20
`width`	Width(ft)	10
`depth_in`	Gravel Depth(in)	4
`vol_cuft`	Derived value`= length * width * depth_in / 12`	calculated

How It Works

Gravel Bed Calculation

Volume (cu ft) = L x W x Depth (ft)

Tons = Cubic Yards x 1.4 (typical for crushed stone)

Gravel weighs roughly 1.3 to 1.5 tons per cubic yard depending on stone type. For drainage beds, use 4 to 6 inches of washed gravel. For decorative paths, 2 to 3 inches is sufficient.

Worked Example

20 x 10 ft gravel path at 4 inches deep.

length = 20width = 10depth_in = 4

01Volume = 20 x 10 x (4/12) = 66.7 cu ft
02Cubic yards = 66.7 / 27 = 2.5
03Tons = 2.5 x 1.4 = 3.5 tons

Ready to run the numbers?

Open Gravel Bed Calculator