Mulch Calculator
Estimate the volume of mulch and the number of bags you need to cover a garden bed at a chosen depth.
m
m
Length & width unit
cm
Depth unit
cu ft
$
Covers 15 m² at this depth · Volume 0.9 m³
0.9 m³
Mulch volume- 1
Bed area (m²)
5 × 3 = 15 - 2
Mulch volume (m³)
15 × 0.06 = 0.9 - 3
Bags needed
0.9 ÷ 0.0566 = 16Rounded up to the nearest whole bag — you cannot buy a fraction of a bag.
How does this calculator work?
Multiply your bed length, width, and chosen depth (all in the same units) to get the mulch volume, then divide by your bag size and round up for the number of bags. At a typical 5-8 cm depth, this calculator also reports cubic yards, cubic feet, and an estimated cost from the price per bag.
Formula
How this is calculated
Enter the bed length and width (in meters or feet) and the layer depth (in centimeters or inches). A typical mulch layer is 5-8 cm (2-3 in) deep: thinner layers do not suppress weeds well, while layers over about 10 cm can starve roots of oxygen. All measurements are converted to meters, then the raw volume is computed as Length × Width × Depth in cubic meters.
The cubic-meter volume is converted to other common units using 1 m³ = 1.30795 cubic yards and 1 m³ = 35.3147 cubic feet, since mulch is often sold loose by the cubic yard or bagged by the cubic foot. The number of bags is the volume divided by the bag size (a standard bag holds 2 cubic feet, about 0.0566 m³), rounded up to the next whole bag because you cannot buy a partial bag.
Multiplying the bag count by the price per bag gives an estimated material cost. The estimate assumes a flat bed and an even layer with no compaction or waste; for irregular shapes, split the area into rectangles and add the results, and consider ordering 5-10% extra to account for settling and spillage.
Frequently asked questions
For most garden beds, aim for a layer of 5-8 cm (2-3 inches). This is enough to retain moisture and suppress weeds without smothering plant roots.
A cubic yard is about 27 cubic feet, so it equals roughly 13.5 standard 2-cubic-foot bags. This calculator rounds the bag count up to the nearest whole bag.
Yes. Mulch settles and some is lost to spillage, so adding 5-10% to the calculated amount is a safe margin, especially for large beds.
Also known as
TG we-Calculate Editorial Team. (2026). Mulch Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mulch-calculator
TG we-Calculate Editorial Team. "Mulch Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/mulch-calculator.
TG we-Calculate Editorial Team, "Mulch Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mulch-calculator
@misc{wecalculate_mulch_calculator, title = {Mulch Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mulch-calculator}}, year = {2026}, note = {TG we-Calculate} }
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