Raised Bed Soil Calculator
Calculate the soil needed to fill a raised garden bed to a chosen depth.
Calculator
| Cubic yards | 1.19 yd³ |
|---|---|
| 1.5 cu ft bags | 22 bags |
| 2 cu ft bags | 16 bags |
How it is calculated
4 ft × 8 ft × 12 in ÷ 12 = 32.0 cubic feet (1.19 cubic yards), about 22 bags of 1.5 cu ft.
About this calculator
The soil for a raised bed is length × width × depth. Because most bags are sold in cubic feet, the calculator also shows the number of 1.5 and 2 cubic foot bags. Soil settles after watering, so beds are often filled a little above the rim.
Filling several beds with bagged soil gets expensive; bulk garden mix from a landscape supplier is usually cheaper per cubic yard if you can have it delivered.
Worked examples
| Project | Cubic feet of soil | Rough cost |
|---|---|---|
| a 4x8 ft raised bed filled 12 in deep | 32.0 ft³ | $41.48 – $107 |
| a 4x4 ft raised bed filled 8 in deep | 10.7 ft³ | $13.83 – $35.56 |
| a 3x6 ft raised bed filled 12 in deep | 18.0 ft³ | $23.33 – $60.00 |
| a 4x12 ft raised bed filled 16 in deep | 64.0 ft³ | $82.96 – $213 |
Buying notes
- Measure the inside of the bed, not the outside of the frame.
- Ask the supplier what is in a garden mix; a blend with compost drains and feeds well.
- For tall beds, filling the bottom with logs or coarse material saves soil.
Quick answers by size
Click a size for the exact quantity and cost.
How to measure and use this calculator
- Measure the inside length and width of the bed.
- Enter the depth you will fill to.
- Read cubic feet, cubic yards and bag counts.
- Consider buying in bulk for several beds.
Common mistakes
- Using outside dimensions instead of inside ones.
- Filling to the very top; soil settles.
- Using plain topsoil only, which can drain poorly in a bed.
Tips
- Fill beds a little above the rim; soil settles after the first watering.
- A blend of roughly equal parts topsoil and compost works well for vegetables.
- For tall beds, fill the bottom with logs or coarse material to save on soil.
Frequently asked questions
How deep should a raised bed be?
Eight to twelve inches suits most vegetables; 18 inches or more helps deep-rooted crops and drainage.
What soil should I use in a raised bed?
A mix of good topsoil and compost is a common choice. A local garden center can recommend a blend for your crops.
How deep should a raised bed be?
Eight to twelve inches suits many vegetables. Deep-rooted crops or poor ground below may justify more.