Mulch Calculator
Cubic Yards, Bags & Landscaping Coverage
Calculate the exact cubic yards or number of bags of mulch, topsoil, gravel, or compost needed for any garden bed, lawn area, or landscaping project. Supports multiple shapes — rectangular, circular, and triangular — with bulk vs bagged cost comparison.
Garden Beds / Areas
Recommended Mulch Depths
| Application | Depth | Notes |
|---|---|---|
| Flower beds | 2–3 inches | Too deep smothers perennials |
| Trees & shrubs | 3–4 inches | Keep 6" away from trunk |
| Vegetable garden | 2–3 inches | Helps retain moisture |
| Pathways / walkways | 4–6 inches | Suppresses weeds thoroughly |
| Slopes / erosion control | 3–4 inches | Use shredded type to lock together |
Bulk vs Bagged Mulch
Bulk mulch (delivered by the cubic yard) is typically 30–50% cheaper than bagged mulch and better for large projects. One cubic yard = 27 cubic feet = approximately 13.5 bags of 2-cubic-foot mulch. For orders over 3 cubic yards, bulk delivery usually makes more financial sense.
Mulch Benefits Beyond Aesthetics
A proper mulch layer reduces soil moisture loss by up to 70%, moderates soil temperature, suppresses weed germination, and adds organic matter to soil as it breaks down. Organic mulches like wood chips also support beneficial microbial activity in the root zone.
What Is the Mulch Calculator?
This mulch calculator tells you exactly how much mulch to order: enter your bed dimensions and desired depth, and it returns the volume in cubic yards and the number of bags. The math is simple but the units trip everyone up, beds measured in feet, depth in inches, mulch sold in cubic yards and 2-cubic-foot bags. One cubic yard covers 324 square feet at 1 inch deep, and the calculator handles rectangular, circular, and irregular beds plus multiple areas in one order.
Mulch Calculator Example
A 30 ft × 8 ft bed mulched 3 inches deep:
Volume = (240 sq ft × 3 in) ÷ 324 = 2.22 cubic yards.
In bags: 2.22 yd³ × 27 = 60 cu ft, ÷ 2 cu ft per bag = 30 bags. At typical prices, roughly $40–$65 per bulk yard delivered versus $3.50–$6 per bag, bulk delivery costs about $90–$145 while bags run $105–$180, so bulk wins on price for anything above 2 yards, if you can move it by wheelbarrow.
Understanding Mulch
Choosing a Mulch Type
Shredded hardwood knits together and stays put on slopes; pine bark nuggets last longer but float and migrate in heavy rain; pine straw is light and cheap in the Southeast; cedar resists insects and decomposes slowly; dyed mulches hold color but check they are made from untreated wood. Compost used as mulch feeds soil best but suppresses weeds least. Rubber mulch does not decompose at all, which also means it never improves your soil.
How Mulch Actually Helps
A proper mulch layer blocks the light germinating weed seeds need, cuts soil moisture evaporation substantially, buffers soil temperature swings, and, as organic mulch breaks down, feeds soil biology and improves structure. That decomposition is why annual top-ups are a feature rather than a flaw, the mulch is slowly becoming soil.
Ordering and Spreading Tips
Have bulk mulch dumped onto a tarp near the largest bed to save cleanup and wheelbarrow distance. A yard of mulch fills roughly 9–14 wheelbarrow loads, and one person can typically spread 2–3 yards in an afternoon. Spread with a rake to an even depth using a ruler stick until your eye is calibrated, most first-timers spread half the depth they intend, which is exactly how projects run out of mulch two-thirds of the way through.
Frequently Asked Questions
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it equals 13.5 bags of the common 2-cubic-foot size, or 9 bags of 3-cubic-foot bags. If a project needs more than about 27 bags (2 yards), bulk delivery is almost always cheaper and avoids dozens of trips.
How deep should mulch be?
2–3 inches around perennials and shrubs, up to 4 inches for coarse mulch in open beds. Less than 2 inches fails to suppress weeds; more than 4 can suffocate roots and hold excess moisture. Keep mulch 2–3 inches away from trunks and stems, volcano mulching against tree bark invites rot and pests.
How much does a yard of mulch cover?
One cubic yard covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches, and 81 sq ft at 4 inches. Divide 324 by your depth in inches for coverage per yard, that single number answers most sizing questions.
How much does mulch weigh?
Dry wood mulch runs 400–800 lb per cubic yard; wet or composted mulch can approach 1,000 lb. A typical half-ton pickup safely hauls 1–2 yards of dry mulch. Stone products are far heavier, about 2,400–2,900 lb per yard, so never substitute stone in a wood-mulch load plan.
When should I mulch, and how often should I top it up?
Mulch in mid-to-late spring after soil warms, and optionally again in fall for winter insulation. Organic mulch decomposes, plan on refreshing 1 inch or so annually. Before topping up, rake the old layer to break crusting and check total depth so you do not creep past 4 inches.
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