Raised bed soil calculator

How the numbers are worked out

Volume is length × width × depth for each bed, times the number of beds, converted to feet. The example above is one 8 × 4 ft bed, 10 in deep: 8 × 4 × (10 ÷ 12) = 26.7 cubic feet.

Conversions use exact factors: 1 cubic yard = 27 cubic feet, and 1 cubic foot = 28.316846592 litres3. Bags are rounded up.

Check the bag. Bag sizes differ by product. Compressed bales (peat, coir) are labelled with their compressed volume, so a bale fills more than its label says, by an amount the label may not state4. The calculator treats every bag as loose fill. Soil also settles after watering, which these numbers do not include.

Depth

• On hardscape or compacted soil, beds for lettuce, beans, cucumbers should be at least 8 inches deep1.
• On hardscape or compacted soil, beds for peppers, tomatoes, zucchini should be at least 12-24 inches deep1.