Topsoil Calculator
Calculate the volume of topsoil, compost, or garden soil required for flower beds, lawns, or raised garden structures.
Calculation Results
Calculated volume of topsoil in cubic feet (including soil compaction allowance).
Calculated volume of topsoil in cubic yards (standard commercial purchase unit).
Calculated volume of topsoil in cubic meters.
How This Calculator Works
To calculate topsoil requirements:
- Enter the length and width of the garden bed or lawn area.
- Specify the depth of topsoil needed (typically 2 to 4 inches for lawn dressing, or 6 to 12 inches for deep vegetable beds).
- Enter a settling buffer (10% is standard to compensate for soil compaction over time).
- The calculator outputs results in cubic feet, cubic yards, and cubic meters.
Formula & Calculations
Topsoil volume is calculated as simple geometric volume:
Volume = Length × Width × Depth
Loose soil settles after watering and compaction, so we scale the volume using the soil settling and waste factor (typically 10% to 15%):
Compacted Volume = Volume × (1 + Settling / 100)
Standard unit conversions scale from the base unit (cubic feet) to cubic yards or cubic meters.
Step-by-Step Calculation Examples
Backyard Garden Bed (20ft x 10ft x 4in depth)
Calculating topsoil requirements for a standard backyard garden bed with a 10% settling allowance.
- length: 20
- width: 10
- depth: 4
- waste: 10
- volume_cu_ft: 73.33 cu ft
- volume_cu_yd: 2.72 cu yd
- volume_cu_m: 2.08 cu m
Frequently Asked Questions
How deep should topsoil be for a new lawn?
For seeding a new lawn, a minimum topsoil depth of 4 to 6 inches is recommended. This provides grass roots with enough organic nutrients and room to grow deep.
How many bags of soil are in a cubic yard?
It takes 27 bags of 1 cubic foot soil, or 13.5 bags of 2 cubic foot soil to equal exactly one cubic yard (27 cubic feet).
Why does soil volume shrink after watering?
Loose bag soil or bulk dirt contains air pockets. Water causes the fine compost particles to settle together, reducing the physical height of the soil by 10% to 15% after application.
What is the difference between topsoil and garden soil?
Topsoil is standard screened soil scraped from the upper layer of earth. Garden soil is topsoil that has been enriched with compost, organic nutrients, and sand to improve drainage and plant health.
How much does a cubic yard of topsoil weigh?
A cubic yard of dry topsoil weighs approximately 2,000 to 2,200 pounds (about 1 ton). If the soil is wet, the weight can increase to 2,600 pounds or more.