🌱 Garden Soil Calculator
Calculate soil volume in cubic yards and bags for garden beds.
Total Soil Volume
How to Use This Calculator
Enter the length and width of each raised bed or garden area in feet, then set the fill depth in inches. Click "Add Another Bed" for multiple beds. Choose your bag size and optionally enter a price per bag to get a total material cost estimate.
Measure each bed length and width in feet. A standard 4x8 ft raised bed is the most common size because you can reach the center from either side without stepping in the soil.
Set the depth in inches. Most vegetables do well with 12 inches. Root vegetables like carrots and parsnips need 18 to 24 inches. Shallow-rooted herbs can get by with 8 inches.
Add all your beds using the "Add Another Bed" button. The calculator sums the total soil volume across all beds.
Choose your bag size. Two cubic foot bags are the most common. For large projects, consider ordering bulk soil by the cubic yard from a landscape supply company, which is typically 40 to 60% cheaper per cubic foot than bagged soil.
Soil Volume Formula
One cubic yard equals 27 cubic feet. A 4x8 ft bed at 12 inches deep holds 32 cubic feet, or about 1.19 cubic yards. That works out to 16 bags of 2 cubic foot soil mix. At a typical price of $8 to $10 per bag, that is $128 to $160 per bed, which makes the case for bulk delivery on larger projects.
Example Projects
Tips for Your Project
Order about 10 to 15% more soil than the calculator shows. Bagged and bulk soil contains air pockets and organic material that compresses after the first few waterings. A bed that looks full on planting day will often settle 2 to 3 inches lower by midsummer. Topping off annually with 1 to 2 inches of compost replaces what decomposed and keeps the soil level where you need it.
For the best growing mix in a raised bed, avoid using pure topsoil. Pure topsoil compacts over time and drains poorly. A blend of roughly 60% topsoil, 30% compost, and 10% perlite or coarse sand gives excellent drainage and aeration. If you are filling large beds, a mix of 1 part compost to 1 part topsoil to 1 part peat moss (the Mel's Mix approach) works very well for most vegetables.
Frequently Asked Questions
How much soil do I need for a raised bed?
Multiply length × width × depth (all in feet) for cubic feet. Divide by 27 for cubic yards. A 4×8 ft bed filled 12" deep needs ~1.2 cubic yards (32 cubic feet).
What is the ideal depth for raised bed soil?
Vegetables with shallow roots: 6 inches. Most vegetables: 12 inches. Root vegetables (carrots, parsnips): 18–24 inches. Perennial herbs: 8–12 inches.
What mix should I use for raised beds?
Mel's Mix: 1/3 blended compost, 1/3 peat moss or coconut coir, 1/3 coarse vermiculite. This provides excellent drainage and aeration.
How many bags of soil per cubic yard?
A 1 cubic foot bag = 1 cu ft. A 2 cubic foot bag = 2 cu ft. One cubic yard = 27 cubic feet = 13.5 bags of 2 cu ft soil.
How much does a cubic yard of soil weigh?
Topsoil: ~2,000 lbs per cubic yard. Garden mix/compost blend: ~1,200–1,500 lbs per cubic yard. Verify delivery truck access for large orders.