Garden project calculator

Raised Bed Soil Calculator

Estimate soil volume, bags, approximate bulk weight and cost for a raised bed using its inside dimensions and fill depth.

Formula reviewed against raised-bed soil planning guidanceUpdated 2026-08-03

Raised bed inputs

Measure inside the bed

US unitsMetric

Length and widthKnown area

Length ftWidth ft

Finished depth inUse the fill depth inside the bed, not the outside wall height.Ordering allowance %Allows for edges, settling and handling.

Bag volume cu ftUse the volume printed on the soil bag.Bag price USD / bagOptional retail comparison price.Bulk price USD / yd3Use the supplier quote for delivered soil mix.Bulk density tons / yd3Use a supplier density when estimating delivered weight.

Soil to order--

Enter dimensions to estimate material.

Bulk volume--

Retail bags--

Project area--

Bulk material cost--

Bag material cost--

Allowance--

Project profile

Material coverage check

Project area12 in fill depth

The drawing is a planning aid and is not a site survey. Measure irregular edges separately and confirm the finished depth with the supplier or installer.

Transparent estimate

Calculation breakdown

1
Project area
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2
Required material
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3
Ordering allowance
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Results are planning estimates. Product coverage, settlement, moisture, site preparation and supplier rounding can change the quantity purchased.

Reference values

Raised bed fill assumptions

Measure inside dimensions

Use the inside length and width of the bed. Subtracting wall thickness prevents overestimating the fill volume.

Fill depth

Measure the soil depth you plan to fill. Leave room for the final grade and avoid compacting the soil unnecessarily.

Soil mix

A raised bed mix may combine soil and compost. The calculator estimates total volume, not the recipe or nutrient quality.

Primary referencesPenn State Extension - Soil Health in Raised Beds Penn State Extension - Raised Bed Garden Guide Penn State Extension - Soil Management

Raised bed soil calculator FAQ

How do I measure a raised bed?

Measure the inside length and width, then measure the intended soil depth. For multiple beds, calculate each bed separately and add the results.

How much soil is needed for a 4 by 8 raised bed?

At 12 inches deep, the bed contains about 11.85 cubic feet before allowance. Use the calculator with your actual inside dimensions and depth.

How many bags fill a raised bed?

Divide the ordered volume by the bag volume and round up. The result depends on the bag size and the allowance selected.

Should I fill a raised bed with potting soil?

Not necessarily. Choose a suitable raised-bed mix for the plants and local conditions; this calculator only estimates the total volume.

Does the result include settling?

Use the ordering allowance for handling and settling, then confirm the mix and delivery quantity with your supplier.