Mulch Calculator
Measure your bed, pick a depth, and get the volume of mulch to order — plus how many standard bags that works out to.
How we calculate
We work out the area of your bed, multiply it by the depth you entered to get a volume, then convert that to cubic yards (or cubic metres). Results are rounded up to the nearest 0.1 cubic yard.
Tip: Mulch settles over time, so ordering slightly more than the calculated amount is recommended.
Assumptions & things to watch
- Mulch settles roughly 10–20% after spreading and watering, so ordering a little extra is normal.
- Bulk mulch is usually sold by the cubic yard or cubic metre; bags are sold by volume, not weight.
- Keep mulch 2–3 in (5–8 cm) clear of tree trunks and plant stems to avoid rot.
Estimates only — always double-check quantities with your supplier before ordering.
Quick tips: Mulch
How deep should mulch be?
2–3 in (5–8 cm) is right for most beds — deep enough to suppress weeds and hold moisture, shallow enough that air and water still reach the roots. Around trees and shrubs keep it under 4 in (10 cm) and pull it back from the trunk.
How many bags are in a cubic yard?
One cubic yard is 27 cubic feet, so it takes about 14 bags at 2 cu ft each, or 9 bags at 3 cu ft. In metric, a cubic metre is about 25 bags of 40 litres.
How much does mulch cost?
Bulk mulch typically runs about $30–$60 per cubic yard delivered, while bagged mulch works out to roughly $3–$6 per 2 cu ft bag. Bulk is almost always cheaper once you pass three or four cubic yards.
How often should you replace mulch?
Top up organic mulch once a year, usually in spring. Wood chip and bark break down over one to two seasons; you rarely need to remove the old layer, just add enough to get back to your target depth.
What type of mulch should you use?
Shredded bark and wood chip last longest and suit beds and borders. Compost feeds the soil but breaks down fast. Gravel or stone suits dry planting and paths but does not improve the soil.