Raised Bed Soil Calculator
Estimate how much soil to buy for a raised garden bed, in cubic feet, cubic yards, and bag count, with bagged-vs-bulk guidance based on your volume.
Part of your self-sufficiency setup. Pair with the Water Needs Calculator when planning food and water storage.
Calculate raised bed soil
Enter inside bed dimensions, fill depth, and the bag size you'll buy. Results, bag count, and a bags-vs-bulk recommendation appear instantly.
26.67 ft³
Based on an 8 ft by 4 ft raised bed filled to 10 inches deep.
How to use this calculator
Enter the inside bed dimensions and your planned fill depth. Pick a bag size or skip bag math entirely. Results, bag count, and a bagged-vs-bulk recommendation update as you type.
Common mistakes
- Using outside frame dimensions. The planting cavity is 1.5–3 inches narrower per side once the boards are accounted for. Always measure inside.
- Planning too shallow a depth. Under 6 inches limits you to lettuce, herbs, and shallow-rooted greens. 10–12 inches handles most veg, including carrots and beets.
- Ignoring year-one settlement. Soil drops 10–15% in the first season after watering and use. Top off the next spring with compost.
- Trusting bag labels without checking. "Garden soil," "raised-bed mix," and "potting mix" are different products. Match the product to what you're growing.
- Not rounding up your order. Add 10% to your calculated volume so you have enough to top off voids around plants and along the edges.
FAQ
How deep should a raised bed be?
Many raised beds are filled to around 8 to 12 inches or more, depending on the crops and growing goals.
Should I use inside or outside dimensions?
Use inside dimensions, since those reflect the actual planting volume.
Can I use this for planter boxes?
Yes. It works for any rectangular growing box or raised planting area.
Should I buy extra soil?
Usually yes. Soil can settle after watering and use, so having a bit extra is helpful.
How much soil do you need for common raised beds?
- 4×4 bed (10 in deep): ~13 cubic feet
- 4×8 bed (10 in deep): ~27 cubic feet
- 4×8 bed (12 in deep): ~32 cubic feet
- Large beds: consider bulk soil delivery
Tips for building productive raised beds
- Use a mix of compost, topsoil, and organic matter
- Plan for soil settling after watering
- Keep beds no wider than 4 ft for easy access
- Consider deeper beds for root vegetables