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Gravel for 400 sq ft
Gravel for 400 ft² at 4 in deep · 267 × 0.5 ft³ (≈50 lb) bag
Gravel for 400 ft² by depth
| Depth | yd³ | ft³ | Bags | Tons | Bulk / bagged cost |
|---|---|---|---|---|---|
| 2 in | 2.47 | 66.7 | 134 | 3.46 | $123 / $737 |
| 3 in | 3.70 | 100.0 | 200 | 5.19 | $185 / $1,100 |
| 4 in | 4.94 | 133.3 | 267 | 6.91 | $247 / $1,468 |
| 6 in | 7.41 | 200.0 | 400 | 10.37 | $370 / $2,200 |
Driveways usually need 4–6 in of compacted base plus a top layer; paths and patios 2–4 in. Gravel weighs about 1.4 tons per cubic yard.
How it is calculated
Volume = area × depth: 400 ft² × (4 ÷ 12) ft = 133.3 ft³; ÷ 27 = 4.94 yd³. 400 ft² is, for example, a 20.0 × 20.0 ft square or a 40 × 10 ft strip.
FAQ
How much gravel do I need for 400 square feet?
At 4 in deep, 400 ft² needs 4.94 cubic yards (133.3 ft³) – about 267 × 0.5 ft³ (≈50 lb) bag. That weighs roughly 6.9 tons.
Is it cheaper to buy gravel in bulk or bags for 400 sq ft?
At typical prices ($50/yd³ bulk vs $5.50 per bag) bulk costs about $247 versus $1,468 in bags, before delivery. Bulk delivery usually wins above about 1 cubic yard.
Other areas: 200 ft² · 250 ft² · 300 ft² · 500 ft² · 600 ft² · 750 ft² · all areas · gravel calculator
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