Mulch & gravel · Use case

How much mulch,
or gravel, or sand.

Enter the length, width, and depth of your bed or area. Get the volume in cubic yards, cubic feet, and bags — for any bulk landscape material.

Recommended depths

How deep to spread.

Depth determines volume — and getting it wrong is the most common mistake. Guidelines by material:

  • Bark mulch (annual refresh): 2 inches
  • Bark mulch (new bed): 3 inches
  • Wood chips: 3–4 inches
  • Pea gravel (paths): 2–3 inches
  • Decorative gravel (beds): 2 inches
  • Base gravel under pavers: 4–6 inches
  • Sand under pavers: 1 inch
  • Playground mulch: 6 inches

Deeper than 4 inches of organic mulch can suffocate roots — more is not better for plants. For gravel under pavers, the opposite is true: insufficient base depth means settling and movement over time.

Coverage reference
1 cubic yardcovers
at 1 inch deep324 ft²
at 2 inches deep162 ft²
at 3 inches deep108 ft²
at 4 inches deep81 ft²
at 6 inches deep54 ft²

Useful when you know area in sq ft, not volume.

Common projects

Material needed by project.

Project Area & depth Material needed
Mulch a small flower bed50 ft² · 2 in0.3 yd³ · 8 ft³
Mulch a medium bed200 ft² · 3 in1.85 yd³ · 50 ft³
Mulch a large landscape500 ft² · 3 in4.6 yd³ · 125 ft³
Gravel path3 × 20 ft · 3 in0.6 yd³ · 15 ft³
Paver base — patio10 × 12 ft · 4 in1.5 yd³ · 40 ft³
Playground mulch15 × 15 ft · 6 in4.2 yd³ · 112.5 ft³
Mulch & gravel FAQ

Common questions.

How much mulch do I need?
Measure the area in square feet, then multiply by the depth in feet (e.g. 3 inches = 0.25 ft). For a 200 sq ft bed at 3 inches deep, that's 50 cubic feet — just under 2 cubic yards.
How many bags of mulch in a cubic yard?
Mulch bags are typically 2 cubic feet. A cubic yard (27 cubic feet) is 13–14 bags. Bulk delivery is usually cheaper for anything over 1 cubic yard.
How deep should mulch be?
For most beds, 2–3 inches of mulch is ideal. Deeper than 4 inches can prevent water and air reaching plant roots. Refresh annually since organic mulch breaks down.
Does this work for gravel and sand too?
Yes — volume math is the same for any bulk material. Just the depth recommendations and bag sizes differ. Bagged gravel is typically 0.5 cubic feet per bag (54 bags per yard).
Related reading

From the blog.

Article
Soil for a Raised Bed →