Mulch Calculator
Enter the area you're covering and your desired depth to estimate how much mulch you'll need, in cubic yards or standard 2 cu ft bags.
Last updated: September 25, 2026
Frequently asked questions
How much mulch do I need for 200 sq ft?
At 3 inches deep, 200 sq ft needs about 1.85 cubic yards before waste allowance - roughly 28 bags of 2 cu ft mulch.
How deep should mulch be?
2–3 inches is standard for most garden beds. Less than 2 inches won't suppress weeds well; more than 4 inches can smother roots and hold too much moisture.
Does mulch depth vary by type of mulch?
Yes - shredded bark and wood chips typically work well at 2-3 inches deep, while finer materials like compost or straw are often applied thinner (1-2 inches) since they break down and compact faster.
How often should mulch be replaced or topped up?
Organic mulch typically breaks down and should be topped up annually, adding just enough to restore the recommended 2-3 inch depth rather than a full fresh layer every year, which can smother plants and cause excess moisture retention around stems.
Does a sloped or uneven bed need extra mulch beyond the basic calculation?
Yes - this calculator assumes a uniform depth across a flat area. For sloped or uneven beds, measure depth at a few different points and average them, or split the bed into flatter sections and calculate each separately, since a single average depth can under-order material for the low spots.
How much mulch do I need for a 15×30 ft bed at 2 inches deep?
15×30 ft is 450 sq ft. At 2 inches deep that's 75 cubic feet, or about 2.78 cubic yards before waste. With a 10% waste allowance, order about 3.06 cubic yards, or roughly 42 bags of 2 cu ft mulch.
What's the difference between buying mulch in bulk (cubic yards) versus bags?
Bulk mulch is delivered by the cubic yard (27 cubic feet) and is usually cheaper per unit for larger beds, while bagged mulch comes in standard 2 cubic foot bags, better suited to small beds or when you don't have room for a delivered pile. This calculator gives both figures so you can compare.