UnitConv

Mulch Calculator

Work out how much mulch you need by volume, bags and weight

Mulch volume
0.5
m³
Cubic yards
0.654
yd³
Cubic feet
17.66
ft³
Estimated weight
200
kg
1050 L bag

Weight is a rough estimate at ~400 kg/m³; actual density varies with material and moisture.

Volume needed0.5 m³

Bar scaled to a 3 m³ reference.

Formula

Volume = area × depth

Bags = ceil( volume / bag volume )

Area and depth are converted to meters first, then multiplied to get cubic meters. Bag counts are rounded up and weight uses a typical bulk density of 400 kg/m³.

What is a Mulch Calculator?

A mulch calculator works out how much mulch, bark, compost or wood chips you need to cover a garden bed at a chosen depth. Enter the bed area directly, or its length and width, plus how deep you want the layer. The tool multiplies area by depth to give the volume in cubic meters, cubic yards and cubic feet, then divides by a standard bag size to estimate the number of bags. It also shows an approximate weight using a typical bulk density, so you can judge delivery and handling. Both metric (m, cm) and imperial (ft, in) units are supported, making it handy for flower beds, borders, vegetable plots and landscaping projects.

How to Use

1. Choose metric or imperial units. 2. Enter the bed area, or switch to dimensions and enter length and width. 3. Enter the depth of mulch you want (5-8 cm / 2-3 in is typical). 4. Toggle bags on to estimate how many bags to buy, or off for bulk volume. 5. Read the volume, bags and estimated weight.

Formula & Definition

Volume = area × depth Bags = ceil( volume / bag volume ) Weight ≈ volume × 400 kg/m³ For example, a 10 m² bed at 5 cm deep is 10 × 0.05 = 0.5 m³, about 10 bags of 50 L and roughly 200 kg.

Interpreting Results

The headline figure is the volume of mulch you need in cubic meters; cubic yards and cubic feet are shown for ordering bulk material. The bag count is rounded up to whole bags, so buy a little extra rather than running short. Weight is an estimate at about 400 kg/m³ - light, dry wood chips weigh less and wet compost weighs much more, so treat it as a planning guide for delivery and lifting. For large beds, bulk delivery by cubic yard is usually cheaper than bagged product.

Frequently Asked Questions

How much mulch do I need? ▾

Multiply the bed area by the depth. For example, 10 m² at 5 cm deep is 0.5 m³. This calculator does it for you and converts to yards, feet, bags and weight.

How deep should mulch be? ▾

5-8 cm (2-3 in) suits most beds: deep enough to suppress weeds and hold moisture, but not so deep it smothers roots. Keep mulch a few centimetres clear of plant stems and trunks.

How many bags of mulch do I need? ▾

Divide the volume by the bag size and round up. A 50 L bag holds 0.05 m³, so 0.5 m³ needs about 10 bags; a 2 cu ft bag is about 0.057 m³.

How much does mulch weigh? ▾

Roughly 400 kg per cubic meter as a planning figure, but it varies widely - dry wood chips are lighter, while wet compost or soil-based mulch can be far heavier.

Bags or bulk delivery? ▾

For small beds, bags are convenient. For anything over about 1 m³ / 1 yd³, bulk delivery is usually cheaper and saves a lot of carrying.

This tool provides general estimates for planning only. Actual coverage and weight depend on the material and its moisture; confirm quantities with your supplier.