Whether you are growing flowers or vegetables, calculating the amount of soil you need for a raised garden bed is fairly straightforward. Topsoil is most often sold by the cubic foot or the cubic yard. First you need to calculate the space you need to fill.
- Measure square footage of your garden bed— if it’s not a perfect rectangle you may need to estimate, by measuring the length and width of your garden bed in feet.
- You will also need to measure the depth of your flower bed— you’ll want the soil to be at least 1-2 inches below the edges of your raised bed to leave you room to work without spilling over. You may also want to leave room for a 1-2 inch layer of mulch over the topsoil to enhance the growing conditions for the plants. Mulch can prevent water loss from evaporation and help to block weeds.
- Convert all your measurements (length, width, depth) to the feet
- Then multiply those three numbers together to get your volume in cubic feet.
- Finally divide this number by 27 (the number of cubic feet in a cubic yard) to get your total volume in cubic yards. Depending on how they are sold in the store, this number will help you figure out how many bags of topsoil to purchase.
To make this process easier, use our built-in soil calculator below. Check out our FAQ page for more conversion information or call us directly for current pricing.