Bark and mulch calculator

At 50 mm deep, each square metre takes about 60 litres of bark once it settles, so a 60 litre bag covers about 1 m².

  • By Steven Stewart
  • Checked 20 October 2026
  • Source: AWBS (Melcourt stockist)

For an L-shape, split it into rectangles and add them up.

metres
metres
mm

Bark suppliers usually quote coverage at 50 mm. Go deeper for weed control or under play equipment.

litres

Check the bag. 50, 60, 70 and 80 litre bags are common.

%
Bags needed4 bags
Bark needed
240 litres
Bulk bags (about 0.54 m³)
1
Volume
0.24 m³
Area
4.00 m²

4 × 1 m at 50 mm deep, plus 20% for settling.

Bulk bag sizes vary between suppliers, so check theirs.

Bark for common areas

At 50 mm deep with 20% for settling, in 60 litre bags.

AreaLitres60 L bagsBulk bags
1 m²6011
2 m²12021
5 m²30051
10 m²600102
20 m²1,200203
50 m²3,000506

How we calculate this

We multiply the area by the depth to get the volume, then add extra because bark settles and packs down once it’s spread.

Melcourt says two 60 litre bags cover about 1.5 to 2 m² at 50 mm, less than the 2.4 m² their volume alone suggests. Adding 20% brings our figure in line with the top of that range.

Litres = area × depth (m) × (1 + settling) × 1,000Bags = litres ÷ bag size, rounded up

Questions people ask

How much does a bag of bark cover?

A 60 litre bag covers about 1 m² at 50 mm deep once it has settled. At 75 mm it covers about two thirds of that.

Should I put membrane under bark?

A permeable weed membrane under bark helps stop weeds coming through and keeps the bark from mixing into the soil. Don’t use plastic sheeting, as water needs to drain through.

What depth of bark under play equipment?

Much deeper than for a border. Play bark under swings and climbing frames is laid far deeper to cushion falls, so check the guidance for your equipment and use the depth it gives.

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