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Soil Calculator

Ready to calculate
Multiple Shapes.
Bag + Bulk Outputs.
All Common Units.
100% Free.
No Data Stored.

How it Works

01Choose Shape

Rectangular, circular, or triangular bed.

02Enter Dimensions

Length, width or radius, and depth.

03Volume Computation

Cubic feet, cubic yards, cubic meters.

04Bag Counts

Equivalent bags for 1, 1.5, and 2 cu ft sizes.

What is a Soil Calculator?

The Soil Calculator computes the volume of soil, mulch, compost, or gravel needed to fill a garden bed, planter, or landscape area. Inputs: shape (rectangle, circle, triangle, L-shape), dimensions, and depth. Outputs: cubic feet, cubic yards, cubic meters, and the number of common bag sizes (1.5 cu ft, 2 cu ft, 40 lb).


Used by landscapers, raised-bed gardeners, contractors ordering bulk topsoil, and DIY homeowners. Bulk soil is sold by the cubic yard (27 cu ft); bagged is by the cubic foot. Calculator handles unit conversions and tells you whether bagged or bulk is the better economic choice for your project size.

How to Use the Calculator

Pick shape: rectangle/square, circle, triangle, or L-shape.
Enter dimensions: length, width, radius, etc. — in inches, feet, or meters.
Enter depth: recommended 6–12 in for raised beds; 4–6 in for top-dressing.
Calculate: Returns volume in cu ft, cu yd, cu m, and number of standard bags.

The Math Behind It

Rectangle: V = length × width × depth


Circle: V = π × radius² × depth


Triangle: V = ½ × base × height × depth


L-shape: sum of two rectangles


1 cu yd = 27 cu ft = 0.7646 cu m. Most bagged soil is 1.5 or 2 cu ft per bag (check the bag).

Real-World Example

Worked Example

4 ft × 8 ft raised bed, 12 in deep:

  • V = 4 × 8 × 1 = 32 cu ft = 1.19 cu yd = 0.91 cu m
  • Bagged (1.5 cu ft): 32 / 1.5 = ~22 bags
  • Bulk: 1.5 cu yd minimum order from most yards
  • At $5/bag bagged ($110) vs $40/cu yd bulk ($60), bulk wins for orders >1 cu yd.

Who Uses It

1
🌱 Raised Bed Gardeners: Order exact soil volume for new beds.
2
🏞 Landscapers: Bid jobs accurately with material estimates.
3
🏠 Homeowners: Plan mulch, gravel, or topsoil deliveries.
4
🧱 Contractors: Calculate fill dirt for grading projects.
5
🌷 Container Gardeners: Size potting mix purchases.
6
♻ Compost Builders: Plan compost pile dimensions and capacity.

Technical Reference

Conversions: 1 cu yd = 27 cu ft = 0.7646 cu m = 202 US gal. 1 cu ft = 7.48 US gal = 28.3 L.

Bag sizes: bulk topsoil 1.5 or 2 cu ft (~50 lb); compost 1 cu ft; mulch 2 cu ft; potting mix 0.75–2.5 cu ft.

Recommended depths:

  • Lawn topsoil: 4–6 in
  • Vegetable raised bed: 8–12 in
  • Perennial bed: 12–18 in
  • Tree planting hole: 2× root ball depth
  • Mulch: 2–4 in
  • Gravel base: 4–6 in for paths

Key Takeaways

For projects over ~1 cu yd, bulk delivery beats bagged on price. Raised beds typically need 6–12 in depth; top-dressing 1–2 in. Add 10% margin for settling. Always confirm bag size when comparing prices — "soil bag" can mean 0.75, 1.5, 2, or 3 cu ft depending on brand.

Frequently Asked Questions

How much soil do I need for a 4x8 raised bed?
32 cu ft (1.19 cu yd) for 12 in deep. For 6 in deep, 16 cu ft. Always add 10% for settling — soil compacts with watering and time.
Bagged or bulk?
Bulk wins price-per-volume above ~1 cu yd. Bagged wins for small jobs, hard-to-access sites, or when you want soil mix variety. Bulk delivery fees can be $50–$150 — factor in.
What's "yards" of soil?
Cubic yards. 1 yard = 27 cu ft, weighs ~2,200 lb (dry topsoil) or ~2,700 lb (wet). A standard pickup truck holds 1.5–2 cu yd.
Should I add 10% extra?
Yes — soil settles 10–15% after watering. Better to have a small leftover pile than to be a bag short.
Can I mix soil types?
For raised beds, common recipe: 60% topsoil + 30% compost + 10% other (perlite, vermiculite, sand) by volume. Adjust ratios for your crop.
How heavy is a cubic yard?
Topsoil: ~2,200 lb dry, 2,700 lb moist. Compost: 1,000–1,500 lb. Mulch: 800–1,200 lb. Gravel: 2,400–3,000 lb. Truck/trailer rated weight matters.

Author Spotlight

The ToolsACE Team - ToolsACE.io Team

The ToolsACE Team

Our specialized research and development team at ToolsACE brings together decades of collective experience in financial engineering, data analytics, and high-performance software development.

Software Engineering Team

Disclaimer

Volume calculations assume uniform depth. Real beds may have irregular depths from settling, slope, or drainage layers. Add a 10% margin for settling and compaction. For structural fill or load-bearing applications, consult a civil engineer — volume estimates are for landscape and garden use only.