Mulch and Soil Calculator
Work out exactly how much mulch or soil your garden bed needs, in cubic metres, cubic yards, and bags, then compare the cost of buying in bulk against buying bagged.
Price comparison (CAD)
Your results
Worked example
A bed that is 5 m long and 4 m wide has an area of 20 m². At a depth of 7.5 cm:
- Volume: 20 m² × 0.075 m = 1.50 m³
- In cubic yards: 1.50 × 1.30795 = 1.96 yd³
- In bags: 1.50 m³ is 1,500 L, and 1,500 ÷ 56.6 = 26.5, so you need 27 bags
- Bulk at $45 per cubic yard: 1.96 × $45 = $88.29
- Bagged at $4.99 per bag: 27 × $4.99 = $134.73
Bulk wins on price here, but remember that bulk soil is usually dropped in your driveway, while bags are easier to move to a backyard bed.
How this calculator works
Mulch and soil are sold by volume. The formula is simple:
Depth is converted from centimetres to metres (divide by 100). Cubic yards use the standard conversion 1 m³ = 1.30795 yd³. Bag counts use a standard bag size of 56.6 L (2 cubic feet), which is the most common size at Canadian garden centres, and always round up, because a part bag is still a bag you have to buy. A little settling is normal: many gardeners add 5 to 10 percent for fresh mulch on a new bed.
Common questions
How deep should mulch be?
For most flower and shrub beds, 7.5 to 10 cm (3 to 4 inches) suppresses weeds and holds moisture well. Around trees, keep mulch a few centimetres away from the trunk to avoid rot.
Is bulk or bagged cheaper?
Bulk is almost always cheaper per cubic yard once you need more than about half a cubic yard, even before delivery fees. Bags win on convenience for small jobs or hard-to-reach beds. Add your local bulk delivery fee to the comparison if you have one.
What size bag does this calculator use?
56.6 L, which is 2 cubic feet, the standard size for mulch and soil at most Canadian retailers. If your bags are a different size, divide your total litres (shown through the m³ result, times 1,000) by your bag size to get your own count.
Should I order extra?
Ordering about 10 percent extra is a common practice to allow for settling and uneven beds. With bags, you can usually return unopened extras, so rounding up is low risk.
Estimates only. Results are provided for planning purposes and are based on the figures and assumptions shown on this page. Actual quantities vary with settling, bed shape, and product density. Verify quantities and prices with your supplier before ordering. Mississippi Maple accepts no liability for purchase decisions made using this calculator.