liminfoMulch & Gravel Calculator
Free web tool: Mulch & Gravel Calculator
Calculate mulch, soil, or gravel needed for your project.
About Mulch & Gravel Calculator
The Mulch and Gravel Calculator helps homeowners, gardeners, and landscapers determine exactly how much material they need for a ground-cover project. Whether you are laying mulch around flower beds, spreading topsoil for a lawn renovation, covering a gravel path, or filling a raised planter box, this tool eliminates the guesswork and prevents costly over-ordering or frustrating mid-project shortages.
The calculation is straightforward: enter the length and width of the area in feet, then specify the desired depth in inches. The tool computes the total square footage, converts depth to feet (dividing by 12), multiplies to get cubic feet, and then divides by 27 to convert to cubic yards — the standard unit sold by landscaping suppliers in bulk. It also tells you how many standard 2-cubic-foot bags (the most common retail bag size) you will need if buying bagged material instead of bulk delivery.
All calculations update in real time as you type. The tool is entirely browser-based — no account, no app download, and no data is sent anywhere. It works equally well for planning mulch for a single tree ring, topsoil for a large lawn section, pea gravel for a play area, or rubber mulch for a playground. Results are displayed in square feet, cubic feet, cubic yards, and number of 2-cubic-foot bags so you can match whichever unit your local supplier uses.
Key Features
- Calculates total area in square feet from length and width inputs
- Converts depth from inches to feet automatically for cubic volume calculation
- Outputs volume in both cubic feet and cubic yards (bulk supplier unit)
- Counts the number of standard 2 cubic-foot retail bags needed
- Default depth preset to 3 inches — the standard recommended mulch depth
- Accepts decimal inputs for precise measurements (e.g., 12.5 ft × 8.25 ft)
- Real-time updates — results recalculate instantly as you type
- 100% client-side calculation — no server, no account, completely free
Frequently Asked Questions
How much mulch do I need per square foot?
At the standard recommended depth of 3 inches, you need 0.25 cubic feet of mulch per square foot of area (3 inches = 0.25 feet). For 100 square feet at 3 inches deep, that is 25 cubic feet or about 0.93 cubic yards. As a rule of thumb, one cubic yard covers approximately 108 square feet at 3 inches deep.
Should I order mulch in cubic yards or bags?
For large areas (over about 3 cubic yards), buying bulk mulch delivered by a landscaping company is typically far more economical. For small projects, retail bags are more convenient despite costing more per cubic yard. The calculator shows both so you can compare. One cubic yard equals 13.5 standard 2-cubic-foot bags.
What depth should I apply mulch?
The general recommendation is 2–4 inches for most organic mulches like wood chips, bark, and shredded leaves. Too shallow (under 2 inches) provides inadequate weed suppression and moisture retention. Too deep (over 4 inches) can suffocate plant roots, promote fungal disease, and create a habitat for pests. The tool defaults to 3 inches, which is the sweet spot for most applications.
Can I use this calculator for topsoil or gravel?
Yes. The volume formula is the same regardless of material: Length × Width × (Depth in inches / 12) = Cubic Feet. Whether you are calculating topsoil for a garden bed, pea gravel for a patio, sand for a sandbox, or rubber mulch for a playground, the same area and depth inputs give you the correct volume in cubic feet and cubic yards.
How do I measure an irregularly shaped area?
For irregular shapes, break the area into rectangles, calculate the volume of each rectangle separately using the calculator, and add the results together. For a circular area (like a tree ring), use the formula A = π × r², where r is the radius. For example, a tree ring with a 4-foot radius has an area of about 50.3 sq ft, which you can enter as Length = 7.1 ft, Width = 7.1 ft (since 7.1² ≈ 50.4).
What does a cubic yard of mulch look like?
One cubic yard is a cube measuring 3 feet × 3 feet × 3 feet. Visually, it looks like a large pile roughly the size of a washing machine. It weighs between 400 and 800 pounds depending on the material and moisture content. Bagged mulch typically comes in 2 cubic foot bags, so you need about 13–14 bags to equal one cubic yard.
How much does a cubic yard of mulch cost?
Prices vary widely by region and material. As a rough guide, bulk hardwood bark mulch costs $20–$45 per cubic yard, while premium colored or rubber mulch can cost $50–$100 or more. Retail bags typically cost $4–$8 each (2 cubic feet), which works out to $27–$54 per equivalent cubic yard — roughly double the bulk price. Always get local quotes for accuracy.
How thick should a gravel path be?
For decorative pea gravel or crushed stone paths, a depth of 2–3 inches is typical for aesthetic coverage. For functional driveways or high-traffic areas, use 4–6 inches of gravel for adequate drainage and stability. Compactable gravel bases for patios and walkways are typically 4 inches deep. Enter your target depth in the calculator to find the cubic yardage needed.