Raised Bed Soil Calculator | Calculate Soil for Raised Garden Beds

Use this raised bed soil calculator to determine the precise amount of soil needed for their raised garden beds.

How Deep Should Raised Bed Soil Be?

• 6-8 inches: Suitable for shallow-rooted plants like lettuce, herbs, and some flowers
• 10-12 inches: Ideal for most vegetables, including tomatoes, peppers, and beans
• 18-24 inches: Necessary for deep-rooted vegetables like carrots and parsnips

For most general gardening purposes, a depth of 10-12 inches is recommended. This depth provides ample room for root growth while balancing soil volume and cost considerations.

Raised Bed Soil Calculator

Bed Size (L x W x D)	Volume (cu. ft.)	Volume (cu. yd.)	Bags Needed (1 cu. ft.)	Bags Needed (2 cu. ft.)
4′ x 8′ x 1′	32.00	1.19	32	16
3′ x 6′ x 0.75′	13.50	0.50	14	7
2′ x 4′ x 10″	6.67	0.25	7	4
5′ x 10′ x 1.5′	75.00	2.78	75	38
6′ x 3′ x 1′	18.00	0.67	18	9
8′ x 4′ x 18″	48.00	1.78	48	24
10′ x 2′ x 8″	13.33	0.49	14	7

1. 4′ x 8′ x 1′:
   • Volume: 4 x 8 x 1 = 32 cu. ft.
   • Cubic yards: 32 ÷ 27 = 1.19 cu. yd.
2. 3′ x 6′ x 0.75′:
   • Volume: 3 x 6 x 0.75 = 13.5 cu. ft.
   • Cubic yards: 13.5 ÷ 27 = 0.5 cu. yd.
3. 2′ x 4′ x 10″:
   • Convert 10″ to feet: 10 ÷ 12 = 0.833′
   • Volume: 2 x 4 x 0.833 = 6.67 cu. ft.
   • Cubic yards: 6.67 ÷ 27 = 0.25 cu. yd.
4. 5′ x 10′ x 1.5′:
   • Volume: 5 x 10 x 1.5 = 75 cu. ft.
   • Cubic yards: 75 ÷ 27 = 2.78 cu. yd.
5. 6′ x 3′ x 1′:
   • Volume: 6 x 3 x 1 = 18 cu. ft.
   • Cubic yards: 18 ÷ 27 = 0.67 cu. yd.
6. 8′ x 4′ x 18″:
   • Convert 18″ to feet: 18 ÷ 12 = 1.5′
   • Volume: 8 x 4 x 1.5 = 48 cu. ft.
   • Cubic yards: 48 ÷ 27 = 1.78 cu. yd.
7. 10′ x 2′ x 8″:
   • Convert 8″ to feet: 8 ÷ 12 = 0.667′
   • Volume: 10 x 2 x 0.667 = 13.33 cu. ft.
   • Cubic yards: 13.33 ÷ 27 = 0.49 cu. yd.

Raised Bed Soil Calculation Formula

The formula for calculating the amount of soil needed for a raised bed is simple, usually cubic feet or cubic yards).

The basic formula is:

Volume = Length x Width x Depth

To calculate the volume in cubic feet:

1. Measure the length, width, and depth of your raised bed in feet
2. Multiply these three measurements together

For example, if your raised bed is 8 feet long, 4 feet wide, and 1 foot deep: Volume = 8 x 4 x 1 = 32 cubic feet

To convert cubic feet to cubic yards (a common unit for bulk soil orders), divide the result by 27: Cubic Yards = Cubic Feet ÷ 27

In our example: 32 ÷ 27 = 1.19 cubic yards

How Much Soil for a 4×8 Raised Bed?

A 4×8 raised bed is a popular size for many gardeners.

Assuming a depth of 1 foot (which is suitable for most plants): Volume = 4 x 8 x 1 = 32 cubic feet

This means you would need 32 cubic feet of soil to fill a 4×8 raised bed with a depth of 1 foot.

If you prefer to order in cubic yards: 32 ÷ 27 = 1.19 cubic yards

You would need approximately 1.2 cubic yards of soil for a 4×8 raised bed with a 1-foot depth.

How Many Bags of Soil Do I Need for a 2×4 Raised Bed?

Assuming a depth of 10 inches (0.83 feet): Volume = 2 x 4 x 0.83 = 6.64 cubic feet

Most bagged soils are sold in cubic feet. Common bag sizes include:

• 0.75 cubic feet
• 1 cubic foot
• 1.5 cubic feet
• 2 cubic feet

To calculate the number of bags needed, divide the total volume by the bag size:

• For 1 cubic foot bags: 6.64 ÷ 1 = 6.64 bags (round up to 7 bags)
• For 1.5 cubic foot bags: 6.64 ÷ 1.5 = 4.43 bags (round up to 5 bags)
• For 2 cubic foot bags: 6.64 ÷ 2 = 3.32 bags (round up to 4 bags)

Always round up to ensure you have enough soil to fill your raised bed completely.