Topsoil Calculator

Calculate how much topsoil you need for a garden bed or lawn. Enter area dimensions and depth to get cubic feet, cubic yards, bags, and estimated weight.

ft

Length of the area to cover with topsoil.

ft

Width of the area to cover.

in

Standard: 6" for new beds, 3" for lawn top-dressing, 12" for raised beds.

cu ft

Cubic feet per bag. Common: 1 cu ft, 1.5 cu ft (40 lb bag ≈ 0.75 cu ft).

%

Extra for settling, uneven ground. Default 5%.

How this calculator works

This topsoil calculator estimates volume in three steps:

  1. Volume in cubic feet: area length × area width × (depth / 12) — converting inches to feet.
  2. Cubic yards: cubic feet / 27 — for bulk delivery.
  3. Bags: if you enter bag size (default 1 cu ft), the calculator divides total volume by bag size and rounds up.

The weight estimate uses topsoil density of ~2,000 lb per cubic yard — much heavier than mulch (~500-800 lb/cu yd).

Formula

volume_cuft = bed_length × bed_width × (depth / 12)
volume_cuyd = volume_cuft / 27
volume_with_waste = volume_cuft × (1 + waste_pct / 100)
bags = ceil(volume_with_waste / bag_size)  [if bag_size > 0]
weight = volume_cuyd_with_waste × 2000  (lb, approximate)

Example

For a 10 × 10 ft bed at 6" depth, 1 cu ft bags, 5% waste:

  • volume_cuft = 10 × 10 × (6/12) = 50 cu ft
  • volume_cuyd = 50 / 27 = 1.852 cu yd
  • volume_with_waste = 50 × 1.05 = 52.5 cu ft
  • bags = ceil(52.5 / 1) = 53 bags
  • weight ≈ 1.944 cu yd × 2000 = 3,889 lb (~1.94 tons)

Important assumptions

  • Standard topsoil depth: 6" for new beds, 3" for lawn top-dressing, 12" for raised beds.
  • Default bag size: 1 cu ft. Some 40 lb bags are ~0.75 cu ft.
  • Topsoil density: ~2,000 lb per cubic yard. Actual weight varies by moisture — wet topsoil can weigh 3,000+ lb/cu yd.
  • Bulk topsoil is sold by the cubic yard. Bagged topsoil is typically 1 cu ft or 40 lb bags.
  • For raised beds, consider a soil mix (topsoil + compost + perlite) — use the Soil Calculator for soil mix volume.

FAQ

How much topsoil do I need for a 10×10 garden bed?
At 6" depth: 50 cu ft (1.85 cu yd). With 5% waste: 52.5 cu ft → 53 bags (at 1 cu ft/bag) or 2 cu yd bulk. Weight: ~3,889 lb (~1.94 tons).
How deep should topsoil be?
6 inches for new garden beds, 3 inches for lawn top-dressing, 12 inches for raised beds. New lawn installation on poor soil: 4-6 inches of topsoil before sod or seed.
How much does a cubic yard of topsoil weigh?
Approximately 2,000 lb (1 US ton) per cubic yard when moderately moist. Wet topsoil can weigh 3,000+ lb/cu yd. Plan delivery capacity accordingly.
How is topsoil different from mulch?
Topsoil is denser (~2,000 lb/cu yd vs mulch's ~500-800 lb/cu yd), used for growing plants. Mulch is lighter, applied on top of soil for moisture retention and weed suppression. Use the Mulch Calculator for mulch projects.
Should I buy bagged or bulk topsoil?
For beds under 2 cubic yards (54 bags at 1 cu ft), bagged is convenient. For larger areas, bulk delivery by the cubic yard is typically 50-70% cheaper. Most suppliers have a 1-2 cubic yard minimum for delivery.