Raised Bed Soil Calculator
Estimate soil volume for one or more raised beds with settling allowance and bag conversion
Soil volume to purchase
How we calculated it
About the Raised Bed Soil Calculator
Raised Bed Soil Calculator estimates the soil or growing-medium volume needed to fill a raised garden bed. It is useful when bed dimensions are known but suppliers sell compost, topsoil or mixes by cubic feet, litres or cubic yards.
A new bed may settle after filling, and many gardeners blend several materials rather than using one product. Calculate total volume first, then divide it among the chosen mix components.
How to Use the Raised Bed Soil Calculator
- Enter the internal bed length, width and fill depth.
- Calculate the total fill volume.
- Choose the supplier unit you need, such as cubic feet, litres or cubic yards.
- If using a soil blend, allocate the total volume among components using the chosen proportions.
How the Calculation Works
For a rectangular raised bed, volume = internal length × internal width × fill depth after converting dimensions to compatible units.
The resulting cubic volume is converted to the selected purchase unit. Bag count is found by dividing by the bag’s labeled volume and rounding up.
Worked example
Raised Bed Soil Calculator Worked Example
8 ft × 4 ft bed filled 1.5 ft deep
Volume = 8×4×1.5 = 48 ft³. That is 48÷27 ≈ 1.78 yd³ before settlement or overfill allowance.
Result guide
Understanding Your Raised Bed Soil Calculator Result
The calculated volume fills the ideal internal geometry. Real beds can need more or less material because of existing soil, logs, drainage layers or settlement.
Before you rely on the answer
Assumptions and Limitations
- Internal dimensions represent the space actually being filled.
- Fill depth is reasonably uniform.
- Settlement and non-soil layers are excluded unless separately allowed for.
Practical tip
Using This Result in Practice
If you are mixing topsoil and compost, calculate each component from the same total volume rather than estimating bags independently. That keeps the blend proportions consistent.
Related calculations
Useful Calculations to Continue With
If the container shape or soil-volume problem is more general, use the Soil Volume Calculator.
If compost is one component of the bed mix, use the Compost Calculator to estimate its share.
Common questions
Raised Bed Soil Calculator FAQ
Should I use inside or outside bed dimensions?
Use internal dimensions because they describe the space available for soil.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard.
Should I add extra soil for settling?
Often yes for a new bed, but the appropriate allowance depends on the mix and how it is placed.