Mulch Calculator Landscaping. Mulch calculations require area and depth. Formula: Cubic Yards equals (Area in sq ft times Depth in inches) divided by 324. Example 500 sq ft bed at 3-inch depth: 500 times 3 divided by 324 equals 4.63 cubic yards, buy 5 yards. Mulch bags: 2 cubic feet per bag standard. One cubic yard equals 13.5 bags. Same example: 4.63 yards times 13.5 equals 63 bags. Bulk delivery cheaper for large areas, bagged convenient for small. Recommended depths: Flower beds 2-3 inches, shrubs 3-4 inches, trees 4-6 inches, vegetable gardens 2-3 inches, pathways 3-4 inches. Deeper better for weed suppression and moisture retention. Too deep suffocates plants and causes rot. Costs: Bulk mulch delivery 25-50 per cubic yard including delivery for 5+ yards. Bagged mulch 3-6 per 2 cubic foot bag. Premium mulch 40-80 per yard. Colored mulch 35-60 per yard. 500 sq ft at 3 inches costs 115-250 bulk or 190-380 bagged. Bulk economical for 3+ cubic yards. Mulch types and characteristics: Shredded hardwood bark most common, 30-40 per yard, lasts 1-2 years, decomposes enriching soil. Cedar mulch natural insect repellent, pleasant smell, 40-60 per yard, lasts 2-3 years, doesn't blow away. Pine bark nuggets decorative, 35-50 per yard, floats in heavy rain, lasts 2-3 years. Cypress mulch very durable, 40-60 per yard, environmental concerns in some regions. Dyed mulch (red, black, brown) colored, 35-60 per yard, color fades first year. Rubber mulch from recycled tires, 50-80 per yard, lasts 10+ years, playgrounds, doesn't decompose. Organic vs inorganic: Organic mulch (wood, bark, leaves) decomposes adds nutrients, requires annual replenishment. Inorganic mulch (rubber, rock, plastic) permanent, no nutrients, higher initial cost. Most gardens use organic for plant health. Coverage rates vary by type: Shredded mulch 100 sq ft per cubic yard at 3 inches. Large nuggets 80 sq ft per yard at 3 inches due to air pockets. Fine mulch 110 sq ft per yard compact coverage. Calculate based on specific type. Settlement: Mulch settles 20-30 percent first year. Add 1-inch top-dressing annually maintains depth. Fresh mulch decomposes losing volume. Plan for annual refreshing budget 30-50 percent of initial. Example landscaping project: 1,200 sq ft beds around house at 3-inch depth. Calculate: 1,200 times 3 divided by 324 equals 11.11 cubic yards. Add 15 percent for settling equals 12.8 yards, buy 13 yards. Cost at 40 per yard: 520 plus delivery 75 equals 595 total or 50 cents per sq ft. Bagged would be 150 bags at 4 each equals 600 materials, similar cost but more labor. Application tips: Remove weeds before mulching. Install landscape fabric under mulch prevents weeds, controversial may restrict water and nutrients. Keep mulch 2-3 inches away from plant stems and tree trunks prevents rot. Don't mulch against house siding attracts termites. Rake mulch level don't pile volcanoes around trees. Refresh annually adds 1-inch maintains depth. Benefits of mulching: Suppresses weeds reducing 70-90 percent of weed growth. Retains soil moisture reduces watering 25-50 percent. Moderates soil temperature protects roots from temperature swings. Prevents soil erosion from rain and wind. Improves soil as organic mulch decomposes adding nutrients. Gives beds finished professional appearance. Common mistakes: Applying mulch against tree trunks and plant stems causes rot and disease. Too much depth (over 4 inches) suffocates plant roots. Not refreshing annually loses benefits as mulch decomposes and thins. Using fresh wood chips pulls nitrogen from soil as decomposes, compost 6 months first. Calculating in cubic feet but buying cubic yards, convert correctly. Estimating area incorrectly, measure beds not entire yard. Pro tips: Order 10-15 percent extra for settling and touch-ups. Have delivery dumped on driveway for easy wheelbarrow access. Mulch in spring after soil warms, in fall before frost. Use metal edging contains mulch prevents washing away. Buy direct from landscape supply yard saves 20-30 percent vs retail bags. Check for weed seeds, quality mulch is weed-free. Alternative mulch materials: Grass clippings free, decomposes fast, thin 1-inch layers only. Leaves shredded free, excellent for vegetable gardens. Straw inexpensive, vegetable gardens, annual replacement. Compost free if homemade, enriches soil immediately. Pine needles (pine straw) natural acidic for azaleas and rhododendrons. Cocoa bean hulls smells like chocolate, toxic to dogs. Stone or gravel permanent, no nutrients, better drainage. Avoid using materials: Non-shredded bark pieces too large. Fresh sawdust robs nitrogen. Hay contains weed seeds. Dyed rubber concerns about chemicals leaching. Landscape fabric debate: geotextile prevents weeds but some gardeners feel it restricts water, nutrients, and earthworm activity. Use under paths and rock mulch, skip under organic mulch in beds. FAQ: How much mulch do I need? Measure length times width of bed in feet, multiply by desired depth in inches, divide by 324 for cubic yards. Bulk or bags? Bulk cheaper for 3+ yards, bags convenient for small areas and vehicles. How often replace mulch? Annual 1-inch top dressing maintains depth. Full replacement every 3-5 years. What depth? 2-3 inches flowers, 3-4 inches shrubs, 4-6 inches trees. Best type? Shredded hardwood for most beds, cedar for longevity, pine for acid-loving plants. Prevents weeds? Yes 70-90 percent reduction when applied 3-4 inches deep.