Mulch & Soil Calculator: 10 × 12 ft bed
Find cubic yards and how many bags of mulch, topsoil or gravel you need for a bed, with a rough cost.
// Bill of materials
Costs are rough, materials only — edit the price to match your quote.
Pre-filled for a 10 × 12 ft bed. Change any value to recalculate, or start from scratch.
How it's calculated
Volume = length × width × depth. We convert depth from inches to feet, add a little extra, then divide by the volume of one bag and round up. Cubic yards is the volume divided by 27 — handy if you're ordering in bulk.
Worked example — 10 × 12 ft bed
- Bed length
- 12 ft
- Bed width
- 10 ft
- Depth
- 3 in
- Bag size
- 2 cu ft bag (mulch)
- Extra
- 5 %
- Price per bag
- 4 $
Nearby sizes
| Room size | Bags to buy | |
|---|---|---|
| 8 × 8 ft bed | 9 bags | Open |
| 8 × 10 ft bed | 11 bags | Open |
| 10 × 10 ft bed | 14 bags | Open |
| 10 × 12 ft bed (this page) | 16 bags | |
| 10 × 16 ft bed | 21 bags | Open |
| 12 × 12 ft bed | 19 bags | Open |
| 12 × 16 ft bed | 26 bags | Open |
| 12 × 20 ft bed | 32 bags | Open |
| 16 × 16 ft bed | 34 bags | Open |
| 16 × 20 ft bed | 42 bags | Open |
| 16 × 24 ft bed | 51 bags | Open |
| 20 × 20 ft bed | 53 bags | Open |
Tips for buying mulch & soil
- Bulk by the cubic yard is far cheaper than bags once you pass about 8–10 bags — compare both.
- 2–3 inches of mulch suppresses weeds without smothering roots; deeper isn't better.
- Keep mulch a couple of inches back from tree trunks and stems to avoid rot.
- Topsoil settles — go a little deeper than the finished height you want.
- For gravel, add landscape fabric underneath to keep it from sinking into the soil.
- One cubic yard covers about 108 sq ft at 3 inches deep — a useful gut check.
Frequently asked questions
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so about 13–14 bags of 2 cu ft mulch. Past roughly 10 bags, bulk delivery is usually cheaper.
How deep should mulch be?
2–3 inches is ideal for most beds. Enter your depth and the calculator handles the volume.
How much area does a cubic yard cover?
About 108 square feet at 3 inches deep, or 162 square feet at 2 inches. Depth drives coverage.
Can I use this for gravel or topsoil?
Yes — pick the matching bag size. The volume math is identical; only the bag size and depth change.