Calculator
Raised Bed Soil Calculator
Quick Answer
Enter bed dimensions, number of beds, fill level, and bag size to estimate cubic feet, cubic yards, bags, and a simple soil mix breakdown.
Raised Bed Soil Calculator
Estimate raised bed soil volume, cubic yards, bags, and a simple mix breakdown.
Formula Explanation
volumeCuFt = lengthFt x widthFt x heightFt x numberOfBeds x fillLevel. cubicYards = volumeCuFt / 27. bagsNeeded = ceil(volumeCuFt / bagSizeCuFt).
Example Calculation
Two 4 ft by 8 ft beds filled 12 inches high at 90% need 4 x 8 x 1 x 2 x 0.9 = 57.6 cubic feet. That equals 2.13 cubic yards, or 29 two-cubic-foot bags.
| Component | Share | Planning role |
|---|---|---|
| Topsoil | 60% | Mineral soil and volume. |
| Compost | 30% | Organic matter and soil structure. |
| Aeration material | 10% | Drainage and pore space. |
Raised Bed Notes
Do not overfill beds. Soil settles over time, and a small gap below the rim helps with watering, compost, and mulch.
FAQ
How does the raised bed soil calculator work?+
It multiplies length by width by height, then multiplies by the number of beds and fill level to estimate cubic feet.
Should I fill raised beds to 100%?+
Many gardeners fill to 80% to 90% so there is room for watering, compost, mulch, and soil settling.
What soil mix does the calculator suggest?+
The optional planning mix is 60% topsoil, 30% compost, and 10% aeration material.
Will raised bed soil settle?+
Yes. Soil settles after watering and over a growing season, so plan for future top-ups.