Mulch / Gravel Volume Calculator
Calculate how much mulch, gravel, soil, or other bulk material you need for any landscaping area.
Mulch in bulk from a landscape supplier is dramatically cheaper than bagged mulch from a home improvement store, usually 40–60% less per cubic yard. But you need to know your volume before calling for a delivery. This calculator gives you that number in both cubic yards (for bulk orders) and bags (if you're hauling it yourself).
One cubic yard of mulch covers approximately 100 sq ft at 3 inches deep, or 160 sq ft at 2 inches deep. A bulk delivery of 3 cubic yards covers a typical small garden bed system.
Standard depths by material
Mulch for weed suppression and moisture retention: 2–4 inches. Less than 2 inches doesn't suppress weeds effectively. More than 4 inches can prevent water penetration and create conditions for root rot. Keep mulch a few inches away from plant stems and tree trunks, "volcano mulching" piled against tree bases causes bark rot and disease. Gravel for paths: 4–6 inches for walkways, 6–8 inches for driveways. Topsoil for garden beds: 6–12 inches. Sand for leveling or play areas: 2–4 inches.
Bulk vs bagged material
Bulk landscape materials (mulch, gravel, topsoil) are sold by the cubic yard from landscape suppliers and delivered by dump truck. Bagged materials are sold in 1, 2, or 3 cubic foot bags from home improvement stores. A cubic yard is 27 cubic feet, equivalent to 13.5 two-cubic-foot bags or 9 three-cubic-foot bags. For quantities under about 2 cubic yards, bagged may be more convenient despite the higher per-unit cost. Above 2 yards, bulk delivery is almost always cheaper and less work.
Coverage rates
One cubic yard covers: 324 sq ft at 1 inch, 162 sq ft at 2 inches, 108 sq ft at 3 inches, 81 sq ft at 4 inches. These are the exact math, in practice, add 5–10% for irregularity in depth and edges. For gravel paths with significant compaction, order 10–15% extra since gravel compacts under foot traffic and loses apparent volume.
Material weight considerations
A cubic yard of mulch weighs approximately 400–800 lbs depending on moisture content. A cubic yard of gravel or stone weighs 2,400–2,900 lbs. A standard pickup truck bed holds about 1–1.5 cubic yards of loose material but should not be overloaded, check your vehicle's payload capacity. Landscape supply deliveries via dump truck are typically 3–10 cubic yards minimum. Some suppliers offer "scoop and haul" where you bring your own truck or trailer.
Frequently asked questions
How often should I refresh mulch?
Organic mulches (wood chips, shredded bark) decompose over time, typically lasting 1–2 years before needing replenishment. Rather than removing old mulch, simply add a fresh 1–2 inch layer on top, checking that total depth doesn't exceed 4 inches. This adds organic matter to the soil as the lower layers decompose.
What type of mulch is best?
Shredded hardwood bark is the most popular, it stays in place, decomposes slowly, and looks neat. Wood chips decompose faster and are excellent around trees. Rubber mulch lasts longer but adds no organic value. Pine bark nuggets are attractive but float in heavy rain. For vegetable gardens, straw is excellent as it's light and improves soil structure as it breaks down.
Can I use gravel for drainage?
Yes, pea gravel and crushed stone are commonly used for drainage around foundations, French drains, and garden beds with drainage issues. French drains typically use 3/4" crushed stone. For surface drainage, a 6-inch layer of gravel over a landscape fabric barrier helps water move through while preventing soil from clogging the stone.