Ordering soil for gardening or landscaping often involves two different units: the cubic yard for bulk materials and the gallon for smaller volumes. Understanding the conversion between these two measures is helpful for accurate project planning, ensuring you purchase the correct amount of soil.
The Direct Volume Conversion
A single cubic yard of volume is equivalent to approximately 202 US liquid gallons. More precisely, one cubic yard converts to 201.97 US liquid gallons. This number is derived from a standard mathematical conversion of volume units.
The calculation begins with the cubic foot, which is the intermediate unit between a cubic yard and a gallon. One cubic foot is equal to 7.48 US liquid gallons. Since one cubic yard contains 27 cubic feet, multiplying 27 by the cubic foot-to-gallon conversion factor (7.48) yields the final number of approximately 201.97 gallons. This precise factor is consistent regardless of the material being measured, as it is solely a conversion of space.
Visualizing a Cubic Yard
The cubic yard is a three-dimensional measurement of space defined by a cube with all sides measuring exactly three feet in length. This means that one cubic yard is equivalent to 27 cubic feet. Visualizing this scale is important when ordering soil, mulch, or compost in bulk.
One cubic yard of material is generally enough to fill the bed of a standard small pickup truck. It is also the equivalent of about 27 standard bags of soil, which are typically sold in one-cubic-foot increments at garden centers. For instance, a raised garden bed that is 4 feet wide by 8 feet long, filled to a depth of 12 inches (1 foot), would require slightly more than one cubic yard of soil.
Practical Use in Landscaping Projects
Knowing that a cubic yard holds about 202 gallons has two main practical applications in landscaping.
Container Filling Estimates
The first is determining how many smaller containers can be filled from a bulk delivery of soil. Since many common gardening containers are sized in gallons, you can estimate that a single cubic yard of soil will fill approximately 40 five-gallon buckets (202 gallons divided by 5 gallons per bucket). This helps manage the movement of soil and plan the number of containers to purchase.
Water Saturation Capacity
The second application involves estimating the water saturation capacity for a new garden bed. If a large raised bed holds exactly one cubic yard of soil, approximately 202 gallons of water would be required to completely fill the pore spaces within that volume. While soil is not entirely empty space, this calculation provides a theoretical maximum for water content, which is helpful when determining initial watering needs or calculating the total capacity of a water reservoir for a self-watering system.