Mulch Calculator

What It Does

This calculator works out how much mulch a bed needs. Enter the area and the depth of the layer — 2 to 3 in is the usual recommendation — and it multiplies the two for the volume, reported in cubic yards, cubic feet and cubic metres. Enter the volume of the bag you are buying and it divides the volume by that, rounding up to whole bags, so you know how many to put in the trolley.

Real-World Usage

Flower beds, tree rings, vegetable patches and the strip along a fence all take mulch by the volume, and the bag you buy sets how many you carry home. Use the calculator to order a bulk load by the cubic yard or to buy bags, and to see how much a deeper layer adds to the cost.

Local Context

Bulk mulch is sold by the cubic yard in the United States and by the cubic metre in most of Europe, while bagged mulch is sold by volume — the 2 cu ft (about 56 L) bag is the US standard and 40 or 50 L bags are common in Europe. A 2 to 3 in (5 to 7.5 cm) layer is the usual recommendation, thinner over shallow-rooted plants.

How deep should mulch be laid?

A 2 to 3 in (5 to 7.5 cm) layer suppresses weeds and holds moisture without smothering roots. Keep it clear of trunks and stems, where a deep pile traps damp against the bark.

How many bags of mulch are in a cubic yard?

A cubic yard is 27 cu ft, so at the standard 2 cu ft bag it is 13.5 bags — buy 14. Smaller 1.5 cu ft bags need 18, and 3 cu ft bags need 9.

How many bags do I need for 100 square feet?

At a 3 in depth the bed takes 25 cu ft, so 13 bags of 2 cu ft. Enter your own bag size and the number follows the volume rather than the area.

Is bagged or bulk mulch cheaper?

Bulk mulch is priced by the cubic yard or metre and is cheaper per unit on a large job, but it needs somewhere to be tipped. Bags cost more per unit and suit small beds — the calculator gives the volume either way.