How Much Soil for a 4x8 Raised Bed?
Get the soil volume in cubic feet and cubic yards, plus how many common soil bags you’ll need for a 4×8 bed.
Worked example
Worked example (depth 12"): depth_ft=12/12=1. Soil_ft³=8×4×1=32. Soil_yd³=32/27=1.185…. Bags: 1.5 ft³ → ceil(32/1.5)=22; 2 ft³ → 16; 3 ft³ → 11.
Why the numbers vary
Bag volume is loose-fill and compaction/moisture can change real volume. Also, many beds aren’t perfect rectangles once you account for edging and corner rounding.
Use the calculator Opens prefilled state.
FAQ
How many bags of soil for a 4x8 raised bed at 12 inches?
32 ft³ total. That’s 16 bags of 2 ft³, 11 bags of 3 ft³, or 22 bags of 1.5 ft³ (ceil).
How much soil is that in cubic yards?
32 ft³ ÷ 27 = 1.185… yd³.
What if my bed is 10 inches deep?
Use depth_ft = 10/12 = 0.8333. Soil = 8×4×0.8333 ≈ 26.67 ft³.
Do I need to add extra for settling?
Often yes. A small buffer (5–15%) can cover settling, but that’s not included in the base formula.
Sources
- Formulas documented on the calculator page.
- Bag volume is based on labeled cubic feet (manufacturer).
Related
Estimates only. If you need accuracy, validate depth, compaction, and spacing with your local guidance.