Mulch vs Topsoil
Mulch and topsoil both arrive in bulk — by the cubic yard or the bag — and both calculators work from the same starting geometry: a measured bed area and a chosen depth. The difference is what the material is for and what the worksheet adds on top of the volume. The mulch calculator estimates how much ground cover you need and how many whole bags to plan for. The topsoil calculator starts from the same area-and-depth volume but adds a user-entered bulk density, so it can also report scenario weight and a whole-package count. Neither page recommends a depth, density, or product — those are inputs you supply from the product information you are using.
What each calculator does
The mulch calculator takes a measured area in square feet, a selected depth in inches, a waste allowance, and the bag yield in cubic feet per bag. Base volume is area times depth, waste is applied once, and the whole-bag count is rounded up only after that step. The adjusted volume is also shown in cubic yards using 1 yd³ = 27 ft³. Its worked example sizes a 200 ft² bed at 3 in: 50 ft³ of base volume, 55 ft³ after a 10% allowance, about 2.04 yd³, and 28 whole bags at a 2 ft³-per-bag label yield. The page stresses comparing the entered yield with the exact product label.
The topsoil calculator also computes base volume as area times depth, then scales by an entered bulk density in pounds per cubic foot to get scenario weight (displayed in short tons using 2,000 lb per ton), and finally divides by an entered package weight to ceiling whole packages. Its worked example estimates 300 ft² at 6 in as 150 ft³ — about 5.56 yd³ — which at 75 lb/ft³ weighs roughly 11,250 lb (5.63 tons), or 282 whole 40 lb packages. The page is explicit that the ton result is conditional on the density you enter, not a universal weight for topsoil.
Side-by-side comparison
| Feature | Mulch calculator | Topsoil calculator |
|---|---|---|
| Primary question | How much ground cover do I need? | How much soil, and how heavy, is my order? |
| Geometry | Area × depth | Area × depth |
| Waste allowance | Applied once before bag ceiling | Applied once before weight and package count |
| Weight output | None | Scenario weight in tons from entered bulk density |
| Package output | Whole bags from entered yield (ft³/bag) | Whole packages from entered pounds per bag |
| Product assumptions | Yield entered by user | Density, moisture basis, and package weight entered by user |
When to use which
Use the mulch calculator when the job is a protective ground cover — a landscape bed you are topping off — and you are buying by volume or by bag. Its worksheet handles the bag-yield comparison that matters at the garden center, and it stays purely volumetric, which matches how mulch is typically sold.
Use the topsoil calculator when you are building or refreshing planting soil and you need to plan around weight — for example, to compare a bulk delivery quoted by the ton with bagged soil sold by weight, or to sanity-check a truckload. Record the density and moisture basis of the specific product beside the result, because the weight estimate changes with the density you enter.
For either material, measure the bed area first with the square footage calculator. If the bed needs organic matter worked into the soil rather than a surface cover, the compost calculator is the companion worksheet for that material.
Where to start
- Mulch calculator — volumetric ground-cover estimate with whole-bag count.
- Topsoil calculator — soil volume, weight, and package count from entered density and package weight.