How topsoil is calculated
Volume (ft³) = length × width × (depth in inches ÷ 12)
Volume to order = volume × (1 + settling %)
Bags = volume to order ÷ cubic feet per bag, rounded upWorked example: a 20 × 10 ft area, 4 in deep
- Volume: 20 × 10 × (4 ÷ 12) = 66.7 ft³.
- With 10% extra for settling: 73.3 ft³, or 2.72 yd³.
- In 0.75 cu ft bags: 73.3 ÷ 0.75 = 97.8, so buy 98 bags.
- Approximate weight: 73.3 × 74 lb = about 5,427 lb, or 2.71 tons.
How heavy is topsoil?
The weight above assumes about 74 lb per ft³, or roughly a ton per cubic yard. This is only a guide, because soil varies by composition and can get considerably heavier when wet. Check the load limit of your vehicle or trailer before collecting it yourself, and ask the supplier what a load weighs.
How much depth do you need?
| Project | Typical depth |
|---|---|
| Overseeding or leveling a lawn | 1/4–1/2 in per application |
| New lawn from seed or sod | 4–6 in |
| Flower beds | 8–12 in of workable soil |
| Vegetable beds | 12 in or more |
These are general guides. Your existing soil matters: if it's already good, you may only need a thinner layer worked into it. A simple soil test can show what your ground is missing.
Settling and raised beds
Loose soil settles after watering, so an exact finish height takes more than the geometry suggests. Raise the allowance to 15–20% for a deep fill, or plan to top up after the first few waterings.
Note that bagged "garden soil" or "raised bed mix" isn't the same as bulk topsoil. Mixes are lighter and designed for specific uses, so choose what suits your project, not only the cheapest bag.
Before you order bulk soil
- Ask whether it has been screened, and if possible look at it before it's delivered.
- Ask where the soil comes from, and whether it could contain weed seeds or debris.
- Call your utility locator service before digging into existing ground.
Finishing with mulch? Use the mulch calculator with the same bed size.