How to Calculate Gravel and Mulch Volume from a Site Plan
The Gravel and Mulch Calculator estimates landscaping material requirements directly from site plans. Trace the area of the project and calculate cubic yards of gravel, mulch, or aggregate needed.
Upload your site plan or landscape drawing, set the scale from the legend or by calibrating from a known dimension, then trace each landscape area—mulch beds, gravel paths, or aggregate zones. Enter the material depth in inches (e.g., 3 inches for mulch, 4–6 inches for gravel base). The tool computes volume in cubic yards or cubic feet and estimates truck loads based on a standard 10 cu yd dump truck.
Use the waste factor to account for compaction, spillage, and uneven spreading. For most projects, 10–15% overage ensures you order enough material without excess.
Material Depth Guidelines
Material depth varies by use. Shallower depths work for decorative coverage; structural or drainage applications need more. The table below gives common ranges:
| Material | Typical Depth |
|---|---|
| Decorative mulch | 2–3 inches |
| Functional mulch (moisture retention) | 3–4 inches |
| Pea gravel (decorative) | 2–3 inches |
| Driveway gravel (base) | 4–6 inches |
| French drain aggregate | 6–12 inches |
Understanding Cubic Yards and Truck Loads
Cubic yards are the standard unit for bulk material. One cubic yard equals 27 cubic feet. To get cubic yards from area and depth: multiply area (sq ft) by depth (ft), then divide by 27. Example: 300 sq ft at 3 inches → 300 × (3/12) ÷ 27 ≈ 2.8 cubic yards.
Most dump trucks hold about 10 cubic yards. Smaller loads may be 5 cu yd. Ordering in truck loads is usually more economical than small bags or half-loads. Use the truck load estimate in the results to plan delivery.
Frequently Asked Questions
How do I calculate cubic yards of gravel from a site plan?
Upload your site plan, set the scale, trace the landscape area with the polygon or rectangle tool, then enter material depth in inches. The formula is: (area_sqft × depth_ft) ÷ 27 = cubic yards.
How deep should I put gravel or mulch?
Decorative mulch: 2–3 in. Functional mulch: 3–4 in. Pea gravel: 2–3 in. Driveway base: 4–6 in. French drain aggregate: 6–12 in.
How many cubic yards are in a truck load?
A standard dump truck holds about 10 cubic yards. Smaller loads may be 5 cu yd. Check with your supplier for exact truck capacities.
What waste factor should I use for gravel or mulch?
10–15% is typical. Use more for uneven terrain or if spreading manually. Bulk delivery often rounds up to truck loads.
Can I use this tool for mulch beds and gravel paths?
Yes. Trace any landscape area—mulch beds, gravel paths, patio base, French drains—and enter the appropriate material depth.