Soil Volume Calculator
Calculate the exact amount of soil needed for garden beds, raised beds, and planting areas. Get results in cubic feet, yards, liters, and bags.
Calculate Soil Needed
Typical: 15-20cm for vegetables, 30-40cm for deep-rooted plants
How Soil Volume Calculation Works
Calculating soil volume helps you purchase the right amount of soil for your garden project, avoiding waste or shortages.
Volume Formulas
Rectangular/Raised Bed: Volume = Length × Width × Depth
Circular Bed: Volume = π × (Diameter/2)² × Depth
Final Volume: Calculated Volume × 1.10 (10% settling allowance)
Soil Depth Guidelines
- 15-20cm (6-8″): Lettuce, herbs, shallow-rooted vegetables
- 30-40cm (12-16″): Most vegetables, flowers, standard gardens
- 45-60cm (18-24″): Tomatoes, peppers, deep-rooted plants
- 60cm+ (24″+): Fruit trees, large shrubs, permanent plantings
Pro Tips for Garden Soil
Mix Soil Types
Blend topsoil (60%), compost (30%), and perlite/vermiculite (10%) for optimal drainage and nutrients.
Test Your Soil
Get a soil test kit to check pH and nutrient levels. Most vegetables prefer pH 6.0-7.0.
Layer for Drainage
Add 5-10cm of gravel at the bottom of raised beds for proper drainage, especially in heavy clay areas.
Account for Settling
Soil compacts 10-15% over the first season. Our calculator includes 10% extra to compensate.
Bulk vs. Bagged
For volumes over 1 cubic yard, bulk delivery is more economical than bags. Compare prices locally.
Mulch on Top
Add 5-8cm of mulch after planting to retain moisture, suppress weeds, and regulate soil temperature.
Frequently Asked Questions
How much soil do I need for a 4×8 raised bed?
For a standard 4×8 foot raised bed that is 12 inches deep, you need approximately 32 cubic feet (0.9 cubic meters) or about 900 liters of soil. This equals roughly 18-23 bags of 40-liter soil.
How deep should soil be for vegetables?
Most vegetables need 30-40cm (12-16″) of soil depth. Shallow-rooted crops like lettuce can thrive in 15-20cm, while deep-rooted plants like tomatoes and carrots prefer 45-60cm for optimal growth.
Should I buy topsoil or garden soil?
Garden soil is better for raised beds and containers as it contains added organic matter and nutrients. Topsoil is suitable for filling large areas or leveling ground. For best results, mix topsoil with compost and perlite.
How many bags of soil equal a cubic yard?
One cubic yard (27 cubic feet or 765 liters) equals approximately 19-20 bags of 40-liter soil, or 14-15 bags of 50-liter soil. Buying bulk soil is more economical for large projects over 1 cubic yard.
Why does soil volume decrease after filling?
Bagged soil is often fluffy and aerated. Once poured and settled (especially after watering), it compacts by 10-15%. Our calculator adds 10% extra to account for this natural settling process.
Can I reuse old potting soil?
Yes, but refresh it first. Remove old roots, mix in fresh compost (25-30%), add perlite for drainage, and consider adding slow-release fertilizer. Old soil may harbor pests or diseases, so inspect carefully.
How much does a cubic meter of soil weigh?
Dry topsoil weighs approximately 1,200-1,400 kg/m³ (2,645-3,086 lbs/yd³). Wet or compacted soil can weigh up to 1,600 kg/m³. Always consider weight when ordering bulk delivery or planning raised bed support structures.
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