Topsoil Coverage Calculator

Measure your garden area with flexible shapes and units. Add depth, waste, and compaction for accuracy. Get clear volume outputs for easy ordering.

Calculator Inputs

Choose the area method that matches your site.
Updates default units. You can still override units.
Typical topdressing: 1–3 cm; beds: 8–15 cm.
same unit
uses length unit
Radius is half the diameter.
uses length unit
uses length unit
Useful when you already know area from a plan.
Covers spillage, uneven grade, and trimming.
Delivered material can settle after spreading.
Optional. Bulk density varies with moisture and texture.
Typical topsoil range: ~1200–1600 kg/m³.
Enter unit price and optional delivery fee.
Price
Fee
Tip: For multiple beds, calculate each section and add volumes.

Example Data Table

Scenario Shape Dimensions Depth Waste Compaction Adjusted Volume
Lawn topdressing Rectangle 12 m × 8 m 2 cm 8% 10% ≈ 2.28 m³
Round tree bed Circle Radius 1.5 m 8 cm 10% 10% ≈ 0.62 m³
Triangular corner fill Triangle Base 10 ft, Height 6 ft 4 in 12% 15% ≈ 1.05 yd³
Examples are illustrative; your site conditions may vary.

Formula Used

  • Area depends on shape: Rectangle = L × W, Circle = π × r², Triangle = ½ × Base × Height, or direct area input.
  • Raw volume: V = Area × Depth (in cubic meters after conversion).
  • Adjusted volume adds allowances: Vadj = V × (1 + Waste%) × (1 + Compaction%).
  • Conversions: m³ to yd³, ft³, and liters are calculated for ordering flexibility.
  • Optional weight: Weight = Vadj × Density (bulk density units converted to kg/m³).

How to Use This Calculator

  1. Select a shape that matches your garden section.
  2. Pick your unit system, then enter dimensions or area.
  3. Enter the soil depth you want to spread.
  4. Set waste and compaction to reduce shortfalls.
  5. Optionally enable weight and pricing for planning.
  6. Click Calculate. Results appear above the form.
  7. Use Download CSV or Download PDF from the results panel.

Accurate Site Measurement

Start by defining the exact area that will receive topsoil, not the whole yard. Measure straight edges with a tape, and use a string line to trace curves. Split irregular spaces into simple shapes and calculate each section separately, then sum the areas before choosing a depth. For long runs, record measurements so you can review them later. Mark corners with stakes to prevent boundary drift.

Choosing a Practical Depth

Topsoil depth depends on your goal and existing grade. Thin layers can smooth low spots and improve seed contact, while deeper layers rebuild raised beds and new lawns. Keep finished levels below edging, paving, and tree flare, and plan a gentle slope away from structures. If you are covering compacted ground, loosen it first so new soil bonds well.

Allowances for Waste and Settling

Fresh topsoil rarely spreads perfectly on real sites. A waste allowance covers spillage, wheelbarrow losses, and trimming along borders. Compaction accounts for settling after watering, walking, and rainfall. Using both factors reduces the risk of ordering short and reworking the job. Where traffic is heavy, increase compaction slightly for safer planning.

Understanding Volume and Unit Outputs

Volume is area multiplied by depth, then converted into purchasing units. Bulk suppliers quote cubic yards or cubic meters, while retail bags are sold by liters or cubic feet. Comparing outputs helps you choose between bulk delivery, pickup loads, or bags for tight access. Bag estimates are helpful for narrow gates and phased work. Always match the supplier unit to the selected output before ordering.

Planning Delivery, Cost, and Handling

When weight limits matter, estimate mass using bulk density, which varies with moisture and texture. Heavier soil may require more trips, stronger wheelbarrows, or a different route. Pricing fields compare suppliers by unit rate plus delivery fees, supporting a realistic budget and schedule. Request screened topsoil for leveling, and consider compost blends for planting beds. Confirm dump location, protect hard surfaces, and spread soil soon after delivery.

FAQs

What depth is common for lawn topdressing?

For turf leveling, many gardeners use a thin layer that does not bury grass blades. Apply lightly, rake evenly, and repeat in sessions if more height correction is needed.

Why include both waste and compaction factors?

Waste covers spillage and trimming losses. Compaction covers settling after watering, foot traffic, and rainfall. Using both gives a more reliable order quantity, especially on uneven sites.

How do I handle an irregular garden shape?

Break the area into rectangles, circles, and triangles, calculate each, then add the areas together. If you already have a measured area from a plan, use the custom area option.

Should I turn on the density option?

Enable density when you need a weight estimate for access limits, rooftop loading, or transport planning. Use a realistic bulk density for your soil condition, because moisture can change weight significantly.

Bulk delivery or bags: which is better?

Bulk is usually efficient for larger volumes and open access. Bags help when gates are narrow, space is limited, or you want staged applications. Compare the calculator’s m³/yd³ output against bag estimates.

Does the calculator include compost or mulch?

This tool targets topsoil volume. Compost and mulch can be estimated the same way, but their density, settling, and recommended depth may differ. Adjust waste, compaction, and density to match the material.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.