Mulch, Soil & Gravel Calculator
Calculate how many cubic yards or standard 2-cubic-foot bags of soil, mulch, or stone you need for garden beds or landscape projects.
Results are estimates. Check physical dimensions before purchasing.
Standard: mulch is 3\", topsoil is 4\", gravel path is 2\"
How to calculate mulch, soil & gravel
Calculating landscaping volumes for aggregate materials like compost, topsoil, river stone, or pine bark mulch involves finding the area of the garden bed and multiplying it by the desired thickness depth.
The Landscaping Formulas
Bed Area = Length (ft) × Width (ft) Volume (Cubic Feet) = Bed Area × (Depth (inches) / 12) Volume (Cubic Yards) = Volume (Cubic Feet) / 27 2-cu-ft Bags Required = Ceiling(Volume (Cubic Feet) / 2)
When to buy bulk vs. bags
Aggregate products are sold in two ways: by the bag at home centers (usually 1.5 or 2.0 cubic feet) or by the scoop/cubic yard from landscaping yards.
- Bagged Materials: Best for projects requiring less than 2 cubic yards. (2 cubic yards equals 27 standard 2-cu-ft bags). Bags are easier to load, transport in cars, and carry directly to specific planter spots.
- Bulk Materials: Highly recommended and significantly more economical for volumes above 2 to 3 cubic yards. Buying bulk aggregates from a landscape nursery, even including their delivery fee, is often half the cost of buying individual bags.
Common material depths
- Garden Mulch: 3 inches. Thick enough to retain moisture and limit weed growth.
- New Lawn Topsoil: 4 to 6 inches. Provides a deep enough nutrient bed for grass roots to anchor.
- Gravel Pathways: 2 to 3 inches. Provides stable coverage without shifting too much underfoot.
Frequently Asked Questions
A depth of 3 inches is recommended for flower beds. This is thick enough to suppress weeds, retain moisture, and regulate soil temperature, without smothering the root systems of your plants.
Standard bags bought at home centers are typically 2 cubic feet. Since 1 cubic yard equals 27 cubic feet, it takes 13.5 bags of 2-cu-ft size to equal 1 cubic yard.
If you need more than 2 cubic yards (equivalent to 27 bags), ordering a bulk pile delivered by a dump truck is almost always more economical. Bagged material is preferred for small touch-ups, hard-to-reach locations, or when transporting in a standard passenger vehicle.