Mulch Calculator

Use it when your task matches one of these common needs: Estimate mulch for a garden bed. Convert square feet and inches deep into cubic yards. It works best when you already know bed area in square feet, depth in inches, bag size, and waste percent.

In plain language: The calculator uses cubic feet = area square feet x depth inches / 12, adjusted cubic feet = cubic feet x (1 + waste percent / 100), cubic yards = adjusted cubic feet / 27, and bags = ceiling(adjusted cubic feet / bag cubic feet). The examples on the page are there so you can compare your inputs with a mulch bed example before copying the answer.

Area square feet: the garden or landscape bed area you want to cover. Depth inches: the finished mulch depth after spreading. Bag cubic feet: the volume printed on the mulch bag, often 1.5, 2, or 3 cubic feet. Waste percent: extra mulch for settling, uneven beds, slopes, and spreading loss.

Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.

This is a planning estimate. Real mulch needs can change with old mulch depth, bed shape, slope, settling, mulch texture, moisture, bag fill, bulk delivery minimums, plant spacing, tree trunks, edging, wind, runoff, and supplier rounding. Also check whether you are topping up old mulch, whether the bag size is 1.5, 2, or 3 cubic feet, and whether bulk delivery has a minimum order.

Multiply square feet by depth in inches, divide by 12 to get cubic feet, then divide by 27 to get cubic yards. The shortcut is square feet x depth inches / 324.

One cubic yard is 27 cubic feet, so it equals 13.5 two-cubic-foot bags. The calculator rounds up because stores do not sell half bags.

Use the finished depth you want after spreading. Two inches is a common light layer, 3 inches is common for many beds, and coarse mulch may be used deeper only when it fits the plant and site. Do not pile mulch against trunks or stems.

If old mulch is still loose and thin, you may only need a top-up layer. If it is matted, sour, piled too deep, or touching trunks, rake it back or remove some before adding more.

Waste percent covers settling, uneven beds, spreading loss, edge cleanup, and small measuring mistakes. Use a small amount for simple beds and more for odd shapes or slopes.

Yes. Add the square footage for each bed, then enter the total area and the same depth. If different beds need different depths, run the calculator separately for each group.

Yes if you already know the square footage. For a circle, area is radius x radius x 3.14. Keep mulch pulled away from the tree trunk instead of making a mulch mound against the bark.

Use cubic yards for bulk quotes and bag count for store pickup. Bagged mulch is easier for small jobs, while bulk delivery can make sense for larger beds if the delivery fee and minimum order work for you.

No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.