How many bags of soil in a cubic yard?
Bags are labelled in cubic feet (or dry quarts for potting mix). A cubic yard is 27 cubic feet.
| Bag size | Bags per cubic yard | Bags per half yard |
|---|---|---|
| 8 qt (0.31 cu ft) | about 87 | about 44 |
| 16 qt (0.62 cu ft) | about 44 | about 22 |
| 0.75 cu ft | 36 | 18 |
| 1 cu ft | 27 | 13.5 (14) |
| 1.5 cu ft | 18 | 9 |
| 2 cu ft | 13.5 (14) | 6.75 (7) |
Some topsoil and compost bags only show a weight, such as a 40 lb bag. Look for the volume elsewhere on the bag; it is usually printed in small type. Weight per bag varies a lot with moisture, so volume is the reliable number to plan with.
How many bags of soil do I need?
bags = length (ft) × width (ft) × depth (in) ÷ 12 ÷ bag size (cu ft), rounded up
Worked example (the default): a 10 × 10 ft area, 3 inches deep.
- Volume: 10 × 10 × 3 ÷ 12 = 25 cubic feet
- With 10% extra: 27.5 cubic feet
- Bags: 28 of 1 cubic foot, 37 of 0.75 cubic feet, 19 of 1.5 cubic feet or 14 of 2 cubic feet
The calculator shows all four counts at once, and highlights the size you picked for the cost line.
Bag coverage at a glance
How many square feet one bag covers at each depth:
| Bag size | 1 in | 2 in | 3 in | 4 in | 6 in |
|---|---|---|---|---|---|
| 0.75 cu ft | 9 | 4.5 | 3 | 2.25 | 1.5 |
| 1 cu ft | 12 | 6 | 4 | 3 | 2 |
| 1.5 cu ft | 18 | 9 | 6 | 4.5 | 3 |
| 2 cu ft | 24 | 12 | 8 | 6 | 4 |
To go the other way, from a number of bags to the area they cover, use the topsoil coverage calculator.
Bags for common jobs
Rounded up, no extra included.
| Job | Cubic feet | 0.75 cu ft | 1 cu ft | 1.5 cu ft | 2 cu ft |
|---|---|---|---|---|---|
| 4 × 4 ft raised bed, 12 in deep | 16 | 22 | 16 | 11 | 8 |
| 4 × 8 ft raised bed, 12 in deep | 32 | 43 | 32 | 22 | 16 |
| 4 × 8 ft raised bed, 2 in compost top-up | 5.3 | 8 | 6 | 4 | 3 |
| 10 × 10 ft bed, 3 in deep | 25 | 34 | 25 | 17 | 13 |
| 100 sq ft of lawn, ¼ in top dressing | 2.1 | 3 | 3 | 2 | 2 |
| 6 ft round bed, 4 in deep | 9.4 | 13 | 10 | 7 | 5 |
For pots, switch the calculator to Pots & planters; it then offers 8-quart and 16-quart bags. The potting soil calculator has a chart by pot size.
Bags or bulk?
Bags make sense when:
- the job is small, roughly under a cubic yard;
- the soil has to go through a house, up stairs, or onto a balcony;
- you want a specific blended product, such as potting mix;
- you can’t store a heap of loose soil, or a truck can’t get close.
Bulk makes sense when:
- you need a yard or more;
- a truck can tip near where the soil is going;
- you’d rather not carry and open dozens of bags.
The fair comparison is price per cubic foot, delivery included:
bags: price per cu ft = bag price ÷ bag size (cu ft) bulk: price per cu ft = (price per yard × yards + delivery) ÷ (yards × 27)
The topsoil cost guide walks through it with your own quotes.
Bag sizes on shelves change from product to product. Always check the volume printed on the bag you are buying, and buy one or two extra if a return is easy.
Questions gardeners ask
- How many bags of soil are in a cubic yard?
- A cubic yard is 27 cubic feet: 36 bags of 0.75 cubic feet, 27 bags of 1 cubic foot, 18 bags of 1.5 cubic feet or 13.5 bags of 2 cubic feet (buy 14).
- How many bags of topsoil do I need?
- Work out the cubic feet (length × width in feet × depth in inches ÷ 12) and divide by the bag size in cubic feet, then round up. A 10 × 10 ft area at 3 inches is 25 cubic feet: 25 bags of 1 cubic foot or 34 bags of 0.75 cubic feet.
- How many 8 quart bags of potting soil make a cubic foot?
- About 3.2. One cubic foot is 25.7 dry quarts, so an 8-quart bag is about 0.31 cubic feet. It takes about 87 of them to make a cubic yard.
- When is bulk soil cheaper than bags?
- Compare the price per cubic foot. For bags, divide the bag price by its size in cubic feet. For bulk, divide the price per yard by 27, after adding the delivery fee spread over the yards you buy.