Topsoil & Raised Bed Soil Calculator

By Vinod Kondeti · Updated October 14, 2026

Raised beds need far more soil than mulch beds because they are filled 6 to 20 inches deep. The default is a 4 × 8 ft bed (32 ft²) at 12 inches. That needs 32 ft³, or 22 bags of 1.5 cu ft, which matches Scotts' raised-bed table.

Area (ft²)Depth (in)Extra for waste / settling (%)Bag size (ft³)

Cost estimate (optional, enter your local prices)

Price per bag ($)Bulk price per yd³ ($)Bulk delivery fee ($)

Cubic yards	–
Cubic feet	–
Cubic meters	–
Bags	–
Cost in bags	–
Cost in bulk (incl. delivery)	–
Cheaper option	–

Working: –

How do I measure for a topsoil project?

Area is length × width of the bed. Use the square footage calculator for odd shapes.
Soil settles after watering. The extra % defaults to 0 here so the result matches Scotts' table; raise it if you want a margin for settling.
For a large bed, compare bulk cubic-yard pricing against bags.

How is the topsoil amount calculated?

Cubic feet = length × width × (depth in inches ÷ 12)
Cubic yards = ft³ ÷ 27
Bags = ft³ ÷ bag size (ft³), rounded up
One bag covers (bag ft³ × 12) ÷ depth (in) square feet; 1 yd³ covers 324 ÷ depth (in) ft²
Extra for waste/settling: volume × (1 + % ÷ 100)
Round bed: π × (d ÷ 2)²; tree ring: π ÷ 4 × (outer² − inner²)
Bulk cost = yd³ × $/yd³ + delivery; bag cost = bags × $/bag

Topsoil calculator questions

How much soil for a 4 × 8 raised bed 12 in deep?

32 ft³: 22 bags of 1.5 cu ft or 32 bags of 1 cu ft (1.19 yd³).

How much for 6 in deep?

16 ft³: 11 bags of 1.5 cu ft or 16 bags of 1 cu ft.

Sources

Estimates only. Use the coverage or bag size printed on your product. Read the mulch guide for worked examples.