Gravel for 400 Square Feet
How much gravel or mulch for 400 sq ft, by depth.
Covering 400 sq ft at 3 inches deep needs about 3.7 cubic yards of gravel (~5.2 tons).
| Depth | Cubic yards | Weight (gravel) |
|---|---|---|
| 2" | 2.47 cu yd | 3.46 tons |
| 3" | 3.7 cu yd | 5.19 tons |
| 4" | 4.94 cu yd | 6.91 tons |
| 6" | 7.41 cu yd | 10.37 tons |
Cubic yards suit bulk delivery; bagged material comes in 2 cu ft bags. Weight shown for gravel (~1.4 tons/yd); mulch is much lighter.
Have exact dimensions? Use the full Gravel & Mulch Calculator to enter length, width and depth.
Last reviewed: November 2026
Data sources: Standard volume and area formulas.
Disclaimer: Quantities are estimates from the area you entered; measure your actual space and add a waste allowance. Material and labor costs vary by region.
Frequently Asked Questions
At a 3-inch depth, about 3.7 cubic yards at 3 inches deep. Deeper coverage needs more — see the table for 2 to 6 inches.
Two inches for a top-up, three to four inches for a fresh path or mulch bed. The table shows the volume at each depth.