Raised Bed Soil Calculator: Bags and Yards to Fill It

How to work it out

Measure the inside length and width of each bed, and add each bed as its own area.
Enter the depth you will fill, usually an inch or two below the top.
Keep some extra. New soil settles over the first few weeks, so the calculator starts with 10%.
Enter the bag size and prices to compare bags with bulk delivery.

How deep to go

Job	Typical depth
Most vegetables and flowers	12 in
Root crops such as carrots	12 to 18 in
Beds on a hard surface	The full height of the bed

These are common starting points. Your site, climate and supplier may call for something different.

What one cubic yard covers

Depth	Area covered
1 in	324 sq ft
2 in	162 sq ft
3 in	108 sq ft
4 in	81 sq ft
6 in	54 sq ft

What to fill it with

Many gardeners use a mix rather than plain topsoil, often topsoil blended with compost. A ready-made raised bed mix is the simplest choice. Check what suits your plants.

Why the weight is only an estimate

Raised bed mixes vary a lot, and compost-heavy mixes weigh much less than topsoil. The calculator starts at a typical figure. Type your supplier's if you have it.

Common questions

How much soil do I need for a 4 by 8 raised bed?

Filled 12 inches deep, a 4 by 8 ft bed holds 32 cubic feet, about 1.19 cubic yards, or about 22 bags of 1.5 cubic feet before any extra for settling.

How many bags of soil fill a raised bed?

Divide the bed's volume in cubic feet by the bag size. The calculator does this, and rounds up to whole bags.

Can I fill the bottom with something cheaper?

Some gardeners put coarse material at the bottom of very deep beds to save soil. Roots still need good soil for most of the depth, so this suits deep beds more than shallow ones.

Doing this job for a customer? Turn your numbers into a free written estimate on QuoteToPaid.

Raised bed soil calculator