Topsoil Calculator
This free topsoil calculator converts the area you’re covering and your desired fill depth into cubic feet, cubic yards, an estimated weight, and a bag count — so you order the right amount of topsoil the first time. Enter your measurements in square feet, get the answer in yards, and this topsoil estimator works whether you’re topdressing a lawn, filling a bed, or building a planter.
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Cubic Yards = (Length × Width × Depth in feet) ÷ 27. A 20×10 ft bed filled 4 inches deep needs about 2.5 cubic yards. Enter your own square footage and depth below for an exact figure in yards, cubic feet, weight, and bags.
Area × Depth ÷ 27 = Cubic YardsHow to Use This Topsoil Estimator
Three inputs, in either shape mode, get you an order-ready number.
Measure your area
Choose rectangular or circular, then enter length and width, or diameter, in feet. This is where “topsoil calculator square feet” comes in — square footage is the starting point either way.
Set your fill depth
Enter the depth in inches, or tap a preset for common jobs — top-dressing, a new lawn, a raised bed, or a deep planter.
Read cubic yards, weight, and bags
The topsoil calculator in yards format is what most bulk suppliers quote — cross-check it against the bag count if the job is small enough to skip a bulk delivery.
Why Use a Topsoil Calculator Before You Order
Topsoil is sold by volume, but most people think about a project in terms of area and depth — a 20-by-10-foot bed, filled 4 inches deep. A calculator for topsoil bridges that gap automatically, converting square footage and fill depth into the cubic feet and cubic yards that bulk suppliers actually quote, then estimating weight so you know what a delivery truck or trailer is really carrying.
Guessing on quantity tends to go one of two ways: ordering too little and paying for a rushed second delivery mid-project, or ordering too much and being stuck disposing of leftover soil. This top soil calculator also builds in a bag-count conversion for smaller jobs, since many home-improvement stores sell topsoil in roughly 0.75-cubic-foot bags rather than by the yard — useful when a project is too small to justify a bulk delivery minimum.
Whether you’re topdressing a lawn the way university turfgrass programs recommend, filling a new garden bed, or building out a raised planter, this topsoil estimator works through the same area-times-depth math every time, with a shape option for both rectangular and circular areas like tree rings or round beds.
How the Topsoil Calculator Works, Step by Step
This topsoil calculator follows the same volume math used in university extension topdressing guides: find the area, apply the fill depth, then convert to the units your supplier actually sells by.
Rectangular area
Volume = Length × Width × Depth, with depth converted from inches to feet by dividing by 12.
Circular area
Volume = π × (Diameter ÷ 2)² × Depth — useful for tree rings, circular beds, or planters.
Cubic feet to cubic yards
Cubic Yards = Cubic Feet ÷ 27, since a cubic yard is 3 ft × 3 ft × 3 ft. Bulk suppliers almost always price and deliver by the yard.
Weight estimate
Weight = Cubic Yards × Density ÷ 2000 — topsoil density varies with moisture and composition, so treat this as an estimate, not a scale-verified figure.
How Deep Should Topsoil Be? A Quick Depth Guide
| Use case | Recommended depth |
|---|---|
| Top-dressing an existing lawn | 1/4″ – 1/2″ |
| Filling in bare or low spots | 2″ – 3″ |
| New lawn from seed or sod | 4″ – 6″ |
| Vegetable or flower beds | 6″ – 8″ |
| Raised beds and deep planters | 10″ – 18″ |
Topsoil Calculator: Worked Examples
Three common yard and garden scenarios worked end-to-end using the same math as the calculator above.
Rectangular bed, 4 inches deep
You’re prepping a new 20-by-10-foot planting bed and want a 4-inch layer of topsoil before seeding.
Given inputs
- Length × Width: 20 ft × 10 ft
- Depth: 4 in
- Density: 2,200 lb/yd³ (default)
Computed outputs
- Area: 20 × 10 = 200 sq ft
- Volume: 200 × (4 ÷ 12) = 66.7 cu ft
- Cubic yards: 66.7 ÷ 27 = 2.47 yd³
- Est. weight: ≈ 2.72 tons
Round planting area, 6 inches deep
You’re building an 8-foot-diameter mulch-and-soil ring around a young tree, filled 6 inches deep.
Given inputs
- Diameter: 8 ft
- Depth: 6 in
Computed outputs
- Area: π × 4² ≈ 50.3 sq ft
- Volume: 50.3 × 0.5 ≈ 25.1 cu ft
- Cubic yards: 25.1 ÷ 27 ≈ 0.93 yd³
- Bags needed: 25.1 ÷ 0.75 ≈ 34 bags at 0.75 cu ft each
Thin top-dressing layer over an existing lawn
You’re top-dressing a 5,000-square-foot lawn with a thin 1/4-inch layer, the technique university turfgrass extensions recommend for smoothing minor low spots without smothering grass.
Given inputs
- Area: 5,000 sq ft
- Depth: 0.25 in
Computed outputs
- Volume: 5,000 × (0.25 ÷ 12) ≈ 104.2 cu ft
- Cubic yards: 104.2 ÷ 27 ≈ 3.86 yd³
- Est. weight: ≈ 4.24 tons — matches the volume math used in university extension topdressing worksheets
Topsoil Calculator Mistakes to Avoid
Mixing up cubic feet and cubic yards
Bagged topsoil is usually priced per cubic foot, while bulk delivery is priced per cubic yard (27 cubic feet). Ordering the wrong unit is the single most common way people under- or over-order.
Not accounting for settling
Freshly delivered topsoil settles and compacts once it’s watered and walked on, often losing 5-10% of its loose volume. Ordering the exact calculated amount can leave you short after the first rain.
Using a dry-soil weight estimate for wet soil
Topsoil weight can roughly double between dry and fully saturated conditions. If you’re hauling it yourself, check your vehicle or trailer’s payload rating against the wet-weight estimate, not the dry one.
Piling too much depth directly on an existing lawn
Topdressing more than about 1/2 inch at once can smother actively growing turf instead of improving it. For thicker layers, work in stages or till the soil first, following standard turfgrass extension guidance.
Confusing topsoil with fill dirt or garden soil
Fill dirt is typically subsoil used for grading and structural fill, not planting. Garden soil is topsoil blended with organic matter. Using the wrong product — or the wrong density for it — throws off both the volume and weight estimate.