About this calculator
Whether you’re filling a raised bed, building up a flower border or spreading soil to level a lawn, the question is the same: how many cubic yards (or bags) do I need? This calculator answers it and adds an allowance for the settling that always happens after loose soil is watered in.
The same math works for garden soil, compost, raised-bed mix and fill dirt.
How to use it
- Enter the length and width of the area to fill.
- Enter the depth of soil you want: 4–6 in under new sod or seed, 8–12 in for flower and vegetable beds, or the full height of a raised bed.
- Keep 10–20% extra for settling. Use the low end for compacted fill, the high end for fluffy bagged mixes.
- Choose a bag size or enter a bulk price to compare.
The formula
Volume = length × width × depth × (1 + settling%)
Cubic yards = cubic feet ÷ 27
Bags = cubic feet ÷ bag size, rounded up
Weight ≈ cubic yards × 1.1 tons
Screened topsoil weighs roughly 2,000–2,200 lb per cubic yard when dry and loose; the calculator uses 1.1 US tons. Moist soil is noticeably heavier, which matters if you plan to haul it yourself.
Worked example
These are the calculator’s starting values and the results they produce:
| Length | 10 ft |
|---|---|
| Width | 4 ft |
| Depth | 12 in |
| Extra for settling | 15 % |
| Bag size | 1 cu ft bag |
| Bulk price per cubic yard | $35.00 |
Tips before you buy
- For raised beds, a mix of about 60% topsoil and 40% compost is a common starting point.
- Bulk delivery usually beats bags once you need more than about 1 cubic yard (27 bags of 1 cu ft).
- Ask for screened topsoil — unscreened soil contains rocks, roots and clods.
- When leveling a lawn, add no more than ½ in at a time over existing grass so it can grow through.
Frequently asked questions
How much topsoil do I need for a 4×8 raised bed?
A 4 × 8 ft bed filled 12 in deep holds 32 cubic feet (1.19 cubic yards). With 15% extra for settling, buy about 37 cubic feet — 1.36 cubic yards, or 37 one-cubic-foot bags.
How many bags of topsoil are in a cubic yard?
A cubic yard is 27 cubic feet, so 27 bags of 1 cu ft, 36 bags of 0.75 cu ft or 13.5 bags of 2 cu ft soil.
How much does a cubic yard of topsoil weigh?
Roughly 1 to 1.1 tons (2,000–2,200 lb) when dry. Wet topsoil can reach 1.5 tons per cubic yard.
How deep should topsoil be for a new lawn?
Aim for 4–6 in of good topsoil under new grass seed or sod. Grass roots grow deeper and the lawn tolerates drought better with more soil.