Quick answer
To calculate yards of dirt: measure length × width × depth in feet, divide by 27 for cubic yards. Shortcut: square feet × depth (inches) ÷ 324. A 10 × 8 bed at 12 inches = 2.96 cubic yards; add 15–25% for settling. Use the free dirt calculator for multi-area projects.
How to calculate yards of dirt (formula)
Bulk dirt is sold by the cubic yard. The core formula is:
Cubic yards = (Length × Width × Depth in feet) ÷ 27
Convert depth in inches to feet by dividing by 12. Combined shortcut:
Cubic yards = Square feet × Depth (inches) ÷ 324
That is how you calculate cubic yards of dirt, yards of dirt, or dirt yardage — they all mean the same volume unit.
Step-by-step: calculate cubic yards of dirt
- Measure length and width of each area in feet.
- Convert depth from inches to feet (inches ÷ 12).
- Multiply length × width × depth for cubic feet.
- Divide by 27 for cubic yards.
- Add settling: topsoil ~25%, fill dirt ~10–15%.
- Optional: multiply by density for tons, or by price for cost.
Worked example: calculate a yard of dirt needed for a 12 × 12 area at 4 inches of topsoil:
- Depth in feet: 4 ÷ 12 = 0.333 ft
- Cubic feet: 12 × 12 × 0.333 = 48 cu ft
- Cubic yards: 48 ÷ 27 = 1.78 cu yd
- With 25% settling: 1.78 × 1.25 = 2.22 cu yd to order
- Weight at 1.0 ton/cu yd: about 1.8 US tons (before settling)
Cubic feet vs cubic yards of dirt
Cubic feet suits bagged soil and small beds. Cubic yards suits bulk truck delivery. Remember: 1 cubic yard = 27 cubic feet. If a cubic feet of dirt calculator gives you 54 cu ft, you need 2 cubic yards before settling.
| Cubic feet | Cubic yards | Typical use |
|---|---|---|
| 13.5 | 0.5 | Small repair / single planter |
| 27 | 1.0 | Pickup-truck load |
| 54 | 2.0 | Small raised bed (bulk starts to win) |
| 81 | 3.0 | Large bed or lawn patch |
| 135 | 5.0 | Grading / multiple beds |
For general volume math without dirt-specific settling, use the cubic yard calculator.
How to calculate dirt from square feet
If you already know square footage, you still need depth. You cannot convert square feet to cubic yards without it. Use:
Cubic yards = sq ft × depth (inches) ÷ 324
Example: 500 sq ft lawn topdressing at 0.5 inch ≈ 500 × 0.5 ÷ 324 = 0.77 cubic yards. Measure area with the square footage calculator, then convert with square feet to cubic yards.
Settling when calculating dirt yards
Calculating dirt yards without settling under-orders almost every project. Loose truck dirt consolidates after placement.
| Material | Settling | Order extra |
|---|---|---|
| Topsoil / black dirt | 20–30% | +25% |
| Fill dirt | 10–15% | +10–15% |
| Compost blend | 25–35% | +30% |
Convert dirt yards to tons
Some suppliers quote dirt by the ton. After you calculate cubic yards:
US tons = Cubic yards × Density (tons per cu yd)
| Material | US tons / cu yd | Example: 3 cu yd |
|---|---|---|
| Topsoil (loose, dry) | 1.00 | 3.0 tons |
| Topsoil (moist) | 1.10 | 3.3 tons |
| Fill dirt (loose) | 1.10 | 3.3 tons |
| Fill dirt (compacted) | 1.25 | 3.75 tons |
Use cubic yards to tons or the density field on the dirt calculator.
Garden beds, fill dirt, and raised beds
The same yardage formula applies, but material choice changes:
- Garden / raised beds: topsoil or soil mix — see how much dirt do I need.
- Grading, pads, backfill: fill dirt — see the fill dirt calculator guide.
- Driveway base: usually gravel, not dirt — use the gravel calculator.
Frequently asked questions
Related tools
Instant estimates: dirt calculator. Volume only: cubic yard calculator. Area first: square footage calculator.