Soil Volume Calculator
Enter the dimensions of the area you need to fill with soil, and the desired depth. The calculator will estimate the total volume of soil required.
Common bag sizes are 1.5 or 2 cubic feet.
How to Calculate How Much Soil You Need
Whether you're starting a new garden bed, filling raised planters, or leveling an area, knowing how much soil to order is crucial. Ordering too little means extra trips and delays, while ordering too much can lead to wasted material and money. This guide will help you accurately estimate your soil needs.
Understanding Soil Volume
Soil is typically measured in cubic feet or cubic yards. A cubic foot is a volume equivalent to a cube that is one foot long, one foot wide, and one foot high. A cubic yard is a much larger volume, equivalent to a cube that is three feet long, three feet wide, and three feet high (which is 27 cubic feet).
The Basic Formula: Length x Width x Depth
The fundamental principle for calculating the volume of a rectangular area is straightforward: multiply its length by its width by its depth. However, consistency in units is key.
Step-by-Step Calculation:
- Measure Length and Width: Use a tape measure to determine the length and width of the area you want to fill. It's often easiest to measure these in feet.
- Determine Desired Depth: Decide how deep you want the soil to be. This is commonly measured in inches for garden beds or planters.
- Convert Units for Consistency: Before multiplying, all measurements must be in the same unit. Since length and width are in feet, convert your desired depth from inches to feet by dividing by 12 (e.g., 6 inches / 12 = 0.5 feet).
- Calculate Volume in Cubic Feet: Multiply your length (in feet) by your width (in feet) by your depth (in feet). The result will be in cubic feet.
- Convert to Cubic Yards (Optional but Recommended for Large Orders): If you're ordering a large quantity of soil, it's often sold by the cubic yard. To convert cubic feet to cubic yards, divide the total cubic feet by 27 (since 1 cubic yard = 27 cubic feet).
- Estimate Bags Needed (if applicable): If you're buying bagged soil, check the volume listed on the bag (usually in cubic feet or liters). Divide your total required cubic feet by the volume of one bag to estimate how many bags you'll need. Remember to round up to ensure you have enough.
Example Calculation:
Let's say you have a raised garden bed that is 10 feet long and 4 feet wide, and you want to fill it with 6 inches of soil.
- Length: 10 feet
- Width: 4 feet
- Depth: 6 inches = 0.5 feet (6 / 12)
- Volume in Cubic Feet: 10 ft * 4 ft * 0.5 ft = 20 cubic feet
- Volume in Cubic Yards: 20 cubic feet / 27 = approximately 0.74 cubic yards
- If bags are 1.5 cubic feet each: 20 cubic feet / 1.5 cubic feet/bag = 13.33 bags. You would need to buy 14 bags.
Tips for Ordering Soil:
- Round Up: Always round up your final soil quantity. It's better to have a little extra than to run short.
- Consider Compaction: Soil can settle and compact over time, especially after watering. You might want to add an extra 5-10% to your depth calculation to account for this.
- Delivery Minimums: Many bulk soil suppliers have minimum delivery quantities (e.g., 1 cubic yard). Factor this into your planning.
- Type of Soil: Different projects require different types of soil (topsoil, garden soil, potting mix, compost). Ensure you're calculating for the correct type.
Using this calculator and understanding the principles will help you confidently plan your next gardening or landscaping project.