Garden soil · Use case

How much soil,
in cubic yards.

Q: What's the difference between topsoil, garden soil, and potting mix?

Topsoil is unscreened native soil — cheap and heavy, used as bulk fill. Garden soil is amended with compost — better for in-ground beds. Raised-bed mix is a blend designed for raised beds (often Mel's mix: 1/3 compost, 1/3 peat, 1/3 vermiculite). Potting mix contains no soil — it's a soilless blend for containers, where drainage matters most.

Enter the inside dimensions of your raised bed, planter, or garden area. Get the soil volume in cubic yards, cubic feet, and liters — plus a reference for how many bags to buy.

Bagged vs bulk

When to switch from bags.

Bagged soil is convenient for small projects, but the price-per-cubic-foot climbs fast for bigger jobs. As a rule of thumb:

Less than 0.5 yd³ (~14 ft³): bagged soil is fine.
0.5 – 1 yd³: bagged works but bulk starts to win on price.
Over 1 yd³ (27 ft³): get bulk delivery — usually 30–50% cheaper.

Most landscape suppliers deliver by the half-yard or yard, and have minimum order quantities (often 2 yd³). Check before you call.

Bag-count reference

1 cubic yard	27 ft³
… in 1.5 ft³ bags	18 bags
… in 2 ft³ bags	14 bags
… in 40 L bags	20 bags
… in 50 L bags	16 bags

Round up — soil settles 10–20% after the first watering.

Common raised-bed sizes

Soil needed by bed size.

Bed size	Depth	Soil needed
4 × 4 ft	8 in	10.7 ft³ · 0.4 yd³
4 × 4 ft	12 in	16 ft³ · 0.6 yd³
4 × 8 ft	10 in	26.7 ft³ · 1.0 yd³
4 × 8 ft	12 in	32 ft³ · 1.2 yd³
3 × 6 ft	10 in	15 ft³ · 0.6 yd³
2 × 8 ft	12 in	16 ft³ · 0.6 yd³

Soil FAQ

Common questions.

How much soil do I need for a raised bed?

Multiply length × width × depth in feet to get cubic feet, or convert to cubic yards (1 cubic yard = 27 cubic feet). A 4×8 ft bed at 10 inches deep needs about 26.7 ft³ or just under 1 cubic yard.

How many bags of soil do I need?

Bagged soil typically comes in 1.5 cubic foot or 2 cubic foot bags. Divide your total cubic feet by the bag size to find the count. For larger projects (over 1 cubic yard), bulk delivery is usually cheaper.

Should I subtract for plants or rocks?

For a new bed, fill to the top — soil will compact and settle by 10–20% over the first season. Order slightly more than calculated, or plan to top up after settling. For existing beds with rocks or established plants, subtract their estimated volume.

What's the difference between topsoil, garden soil, and potting mix?

Topsoil is unscreened native soil — cheap and heavy, used as bulk fill. Garden soil is amended with compost — better for in-ground beds. Raised-bed mix is a blend designed for raised beds (often Mel's mix: 1/3 compost, 1/3 peat, 1/3 vermiculite). Potting mix contains no soil — it's a soilless blend for containers, where drainage matters most.