Calculate the project volume, divide it by the volume of one bag, and round up to a whole bag.
Bag quantity tool
Bags of Topsoil Calculator
Calculate how many whole bags of topsoil to buy from project dimensions, desired depth and the exact volume printed on the bag.
No signupUS & metricInstant results
Convert your project into bags
Use bag volume, not bag weight, for the conversion.
Estimated result
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Enter the project details and calculate.
Bag volume
Use the volume on the label, not the bag weight
Two bags with the same weight can contain different volumes because moisture, compression and material composition differ.
Litres
Metric garden products commonly state nominal volume in litres. One thousand litres equals one cubic metre.
Cubic feet
US bags frequently use cubic feet. Twenty-seven cubic feet equals one cubic yard.
Quarts or gallons
Smaller products may use dry or liquid-style units. Enter the unit exactly as printed and verify the label definition.
Purchase rounding
The exact answer and the buy answer are deliberately different
A calculation may produce 22.3 bags, but a retailer cannot sell 0.3 of a sealed bag. The result therefore reports both the exact requirement and 23 whole bags.
Coverage per bag
Coverage changes with depth. The same 40-litre bag covers twice as much area at 2 cm as it does at 4 cm.
Bag volume ÷ desired depth = area covered per bagBuying control
Keep unopened surplus returnable where possible
A small buffer protects the project from settlement and measurement error, but excessive overbuying ties up money and creates disposal problems.
Check whether damaged or opened bags can be returned, and store bags dry so product condition does not change before use.
Frequently asked questions
Topsoil bag calculator questions
Use volume. Weight changes with moisture and density and does not directly describe how much space the soil will fill.
Retail bags are sold whole. A result such as 12.2 bags means you need to buy at least 13 bags.
Yes. Enter each printed bag volume separately and compare the resulting whole-bag count and price.