Cubic Feet Soil Calculator

Enter Soil Project Details

Use one unit system for dimensions. The calculator converts each dimension into feet internally.

Soil area shape

Choose the closest shape for your project.

Dimension unit

All dimensions use this selected unit.

Length

Used for rectangular, triangular, and trench shapes.

Width or triangle base

For triangle, this is the base width.

Soil depth

Use average depth for uneven ground.

Diameter

Used only for circular beds.

Waste allowance (%)

Covers spills, edge loss, and trimming.

Compaction allowance (%)

Adds volume for settling after placement.

Soil density (lb/ft³)

Typical loose soil may vary by moisture.

Bag size (ft³)

Common bags are 0.75, 1, 1.5, or 2 ft³.

Cost per bag ($)

Used for total purchase estimate.

Delivery cost ($)

Enter zero when not needed.

Formula Used

Rectangular or trench volume: Length × Width × Depth

Circular bed volume: π × (Diameter ÷ 2)² × Depth

Triangular area volume: 0.5 × Length × Base Width × Depth

Final purchase volume: Base Volume × (1 + Waste %) × (1 + Compaction %)

Cubic yards: Cubic Feet ÷ 27

Bags needed: Ceiling(Final Cubic Feet ÷ Bag Size)

The calculator first converts dimensions into feet. Then it applies the selected shape formula, adds waste, adds compaction allowance, and estimates bags, weight, and cost.

How to Use This Calculator

Select the shape that best matches your soil project.
Choose the dimension unit used for your measurements.
Enter length, width, depth, or diameter as required.
Add waste and compaction percentages for practical planning.
Enter bag size, bag cost, density, and delivery cost.
Press the calculate button to see results above the form.
Use the CSV or PDF button to save the estimate.

Example Data Table

Project	Shape	Dimensions	Depth	Waste	Compaction	Estimated Use
Raised garden bed	Rectangular	8 ft × 4 ft	1 ft	8%	10%	Bagged topsoil
Round planter	Circular	6 ft diameter	0.75 ft	5%	8%	Potting mix
Drainage trench	Trench	30 ft × 1.5 ft	1.25 ft	10%	15%	Backfill soil
Corner landscape fill	Triangular	10 ft × 7 ft base	0.8 ft	7%	12%	Bulk garden soil

Understanding Soil Volume

Soil work starts with a question. How much material will fill the space? A cubic feet soil calculator answers that question before ordering, hauling, or spreading begins. It converts project dimensions into a volume. It also helps compare bags, yards, weight, and cost.

Why Cubic Feet Matter

Cubic feet are useful because many bagged soils are sold by this measure. Raised beds, planters, lawn patches, drainage trenches, and small construction fills can be measured with the same method. When a project is larger, cubic feet can be changed into cubic yards. That makes bulk orders easier to discuss with suppliers.

Planning With Real Conditions

Real soil projects rarely match perfect geometry. Loose soil settles after watering and compaction. Edges can be uneven. Some material may spill during delivery or spreading. This calculator includes waste and compaction allowances for that reason. Adding a small allowance can prevent a shortage near the end of the job.

Using Shape Options

Rectangular beds are common, but not every soil area is rectangular. Circular beds, triangular areas, and trenches need different formulas. Selecting the right shape keeps the estimate closer to the real site. Always measure the longest useful dimensions. Use average depth when the ground is uneven.

Cost And Bag Planning

A volume number is helpful, but purchase planning needs more detail. Bag size, soil density, and bag price turn the estimate into bags, weight, and cost. The calculator rounds bags upward because partial bags cannot usually be bought. This gives a practical shopping list instead of only a mathematical answer.

Best Measuring Tips

Measure after clearing debris and marking the final edges. Record dimensions in the same unit when possible. For inches, enter the unit selector correctly. For bulk soil, confirm whether the supplier sells by loose cubic yard or compacted cubic yard. Moisture also changes weight, so density values should be treated as planning estimates.

Final Check

Use the results as a project estimate. Recheck unusual shapes, slopes, and deep fills. For structural backfill, follow project specifications. For gardens, allow room for mulch and plant roots. A careful soil volume estimate saves trips, reduces waste, and keeps work moving.

FAQs

1. What does this cubic feet soil calculator measure?

It measures the soil volume needed for beds, planters, trenches, fills, and similar construction projects. It also estimates cubic yards, bags, weight, and cost.

2. Should I use exact or average depth?

Use average depth when the ground is uneven. Measure several points, add them together, and divide by the number of measurements.

3. Why does the calculator add waste?

Waste allowance covers spills, edge trimming, uneven grades, and small measuring errors. It helps prevent running short during spreading or filling.

4. What is compaction allowance?

Compaction allowance adds extra volume for soil that settles after watering, walking, tamping, or natural compression. It is useful for practical ordering.

5. How many cubic feet are in one cubic yard?

One cubic yard equals 27 cubic feet. Divide cubic feet by 27 to convert a soil estimate into cubic yards.

6. Can I use this for circular garden beds?

Yes. Choose the circular shape, enter the diameter and depth, and the calculator will apply the round bed formula automatically.

7. Why are bag counts rounded up?

Soil bags are sold as whole units. The calculator rounds upward so the purchase estimate is practical and avoids partial bag results.

8. Is soil weight always accurate?

No. Soil weight changes with moisture, organic content, sand, clay, and compaction. Treat the weight result as a planning estimate.