Garden Soil Volume Calculator
Soil Volume for Common Bed Sizes
Cubic feet and cubic yards at different depths
| Bed Size | 6" Deep | 8" Deep | 10" Deep | 12" Deep |
|---|---|---|---|---|
| 4×4 ft | 8 cu ft | 10.7 cu ft | 13.3 cu ft | 16 cu ft |
| 4×8 ft | 16 cu ft | 21.3 cu ft | 26.7 cu ft | 32 cu ft |
| 4×12 ft | 24 cu ft | 32 cu ft | 40 cu ft | 48 cu ft |
| 3×6 ft | 9 cu ft | 12 cu ft | 15 cu ft | 18 cu ft |
| 6×6 ft | 18 cu ft | 24 cu ft | 30 cu ft | 36 cu ft |
| 2×8 ft | 8 cu ft | 10.7 cu ft | 13.3 cu ft | 16 cu ft |
| 3×8 ft | 12 cu ft | 16 cu ft | 20 cu ft | 24 cu ft |
| 5×10 ft | 25 cu ft | 33.3 cu ft | 41.7 cu ft | 50 cu ft |
How We Calculate This
This garden soil volume calculator uses established formulas and industry-standard data to provide accurate estimates.
- Enter your specific values into the calculator fields above
- Our algorithm applies the relevant formulas using your inputs
- Results are calculated instantly in your browser — nothing is sent to a server
- Review the detailed breakdown to understand how each factor affects your result
These calculations are estimates based on standard formulas. For critical decisions, always consult a qualified professional.
How to Convert Oven Recipes to Air Fryer
This calculator determines the volume of soil or amendment needed to fill a garden bed based on its dimensions.
The basic rule:
- Rectangular beds: Volume = Length x Width x Depth
- Circular beds: Volume = π x (Diameter/2)² x Depth
- L-shaped beds: calculated as two overlapping rectangles minus the overlap
- Depth conversion: inches are converted to feet (÷ 12) for cubic foot calculations
- Cubic yards: divide cubic feet by 27 — this is the standard bulk delivery unit
- Add 10% extra for settling, especially with raised beds that will compact over the first season
Buying in bulk (by the cubic yard) is usually cheaper than bags for amounts over 1 cubic yard. A standard pickup truck bed holds about 2 cubic yards of soil.
When Would You Use This Calculator?
This garden soil volume calculator is designed for anyone who needs quick, reliable estimates without complex spreadsheets or professional consultations.
- When you need a quick estimate before committing to a purchase or project
- When comparing different options or scenarios side by side
- When planning a budget and need to understand potential costs
- When you want to verify a quote or estimate you've received from a professional
- When teaching or learning about the concepts behind these calculations
Frequently Asked Questions
How deep should a raised bed be?
Most vegetables need 8-12 inches of soil depth. Root vegetables like carrots need 12+ inches. Shallow herbs and lettuce can grow in 6 inches. For raised beds on concrete or poor soil, 12-18 inches is recommended.
How much does garden soil weigh?
Garden soil weighs approximately 75-100 pounds per cubic foot when dry, and up to 110 pounds when wet. A cubic yard of soil weighs roughly 2,000-2,400 pounds (1-1.2 tons). Compost is lighter at about 40-60 lbs/cu ft.
Should I fill a raised bed entirely with soil?
For deep beds (18+ inches), you can use the 'lasagna method' — fill the bottom third with logs, branches, and leaves, the middle third with compost and organic matter, and the top third with quality garden soil. This saves money and improves drainage.
Is it cheaper to buy soil in bulk or bags?
Bulk soil (delivered by the cubic yard) is typically $30-$60 per cubic yard. Bagged soil costs $5-$10 per cubic foot, or $135-$270 per cubic yard. Bulk is much cheaper for larger projects but requires delivery access.
How much does soil settle after filling a raised bed?
New soil typically settles 10-20% in the first year. Plan to overfill by that amount, or top off with compost after the first growing season. Soil that has been screened and amended tends to settle less.