Topsoil Calculator
Calculate how many cubic yards, and bags, of topsoil you need for a garden bed.
How we calculate it
Volume = Bed area × Depth, converted to cubic yards. No waste factor is applied — topsoil spreads and settles predictably, so this calculator estimates the volume for your chosen depth directly.
Understanding your estimate
Order too little topsoil for a raised bed and you stop halfway through filling it, waiting on a second trip while everything you already planted sits in dirt that's inches too shallow. Order too much and a pile of extra soil sits in a yard that didn't have room to spare in the first place. The formula behind this calculator is short: bed area times depth, nothing layered on top. What's worth explaining is what this calculator leaves out, and why.
A raised bed, worked out
Take the calculator's own default when you switch it to imperial: a 10 ft by 10 ft bed, filled 3 in deep.
- Convert the depth to feet, since the formula runs in feet throughout: 3 in ÷ 12 = 0.25 ft.
- Bed area: 10 × 10 = 100 ft².
- Volume: 100 × 0.25 = 25 ft³.
- In cubic yards, the unit bulk topsoil gets sold and delivered by: 25 ÷ 27 ≈ 0.93 yd³.
- In 0.75 ft³ bags, the standard retail size at a home center: 25 ÷ 0.75 = 33.3, rounded up to 34 bags.
Why there's no waste factor field
This calculator never asks for a waste percentage. Concrete, tile, and drywall all get that field on this site, because spillage, cuts, and an uneven subgrade genuinely change how much of those materials you end up using. Topsoil doesn't behave that way. It spreads and settles into a bed predictably enough that the volume calculated for a given depth is close to what you'll actually use, which is why the Mulch Calculator shipped without a waste factor first. This calculator follows the same rule for the same reason.
Why this stops at volume, not weight
Our Gravel Calculator adds a density field and reports weight, because gravel and stone are sold and hauled by the ton, and how much a load weighs changes what it costs to deliver. Topsoil isn't sold that way. Home centers and landscaping suppliers price it by the bag or in bulk by the yard, the same way they price mulch. So this calculator follows the Mulch Calculator's logic, area times depth converted straight into bags, instead of the Gravel Calculator's, density times volume converted into weight, even though a shopper might expect the two dirt-and-stone calculators to work the same way.
Why the bag count always rounds up
33.3 bags becomes 34, never 33. Every calculator on this site rounds a purchase quantity up, and this one is no exception. One extra bag costs you the price of a bag you can return or use on the next bed. Coming up short mid-project costs you a second trip to the store, usually on a day you'd rather not make it. The test suite for this calculator backs this up directly: adding depth to a bed never lowers the bag count, in either bag size.
One number here is an estimate, not a spec
The 0.75 ft³ bag is a standard retail size for topsoil at US home centers. The 50-liter bag this calculator uses in metric mode isn't from any official spec; it's the same size CalcCraft already assumed for the Mulch Calculator, because 50 L is a common bag size for soil in metric markets, and suppliers vary. And the bed itself is treated as a clean rectangle, length times width, the same simplification every calculator on this site makes, even though a real garden bed curves and narrows in ways a tape measure has to average out.