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Raised Bed Soil Calculator
Garden Material Calculator
Raised Bed Soil Calculator
Calculate soil volume for one or more raised beds in cubic feet, cubic yards, liters, and whole bags, including an adjustable settling allowance.
Estimate raised bed soil
How to use the raised bed soil calculator
Enter the inside length and width of one bed, the planned fill depth, and the number of identical beds. Add a settling allowance if you expect the loose mix to compress. For bagged soil, copy the cubic-foot volume printed on the bag; the optional price field estimates the whole-bag total.
Raised bed soil formula
Total soil = length x width x (depth in inches / 12) x number of beds x allowance factor
The result is first calculated in cubic feet. Cubic yards equal cubic feet divided by 27, and liters equal cubic feet multiplied by 28.316846592. Bag quantity is the total cubic feet divided by the volume of one bag, rounded up.
Worked example
Two beds measuring 8 feet by 4 feet and filled 12 inches deep have a base volume of 64 cubic feet. With a 10 percent settling allowance, the target becomes 70.4 cubic feet, or about 2.61 cubic yards. At 1.5 cubic feet per bag, that is 47 whole bags. A bulk delivery may be more practical at this scale.
Choosing a soil blend
Volume and soil quality are separate decisions. University of Minnesota Extension suggests a raised-bed mixture of roughly one-half to two-thirds topsoil and one-third to one-half plant-based compost. Local materials, drainage, crops, and soil test results should guide the final blend. Avoid assuming the entire bed must be pure compost.
Accuracy and assumptions
- Dimensions are inside measurements; thick bed walls are not part of the fill volume.
- All beds are assumed to have the same dimensions and fill depth.
- The settling allowance increases volume before bags are rounded.
- The calculator does not subtract logs, branches, existing soil, irrigation components, or drainage layers.
- Bulk suppliers may sell only in fixed increments and may use their own truck-capacity minimums.
Frequently asked questions
Should I measure the outside or inside of a raised bed?
Use inside dimensions because they describe the space that actually holds soil. Outside dimensions overstate the volume when walls are thick.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard. Divide cubic feet by 27 when comparing a bagged-soil estimate with a bulk supplier.
Do raised beds settle after filling?
Loose mixes commonly settle after watering and time. The adjustable allowance lets you plan for that without locking every project to the same percentage.
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Sources and review
Soil-blend context was checked against the University of Minnesota Extension guide to raised bed gardens. Unit conversions use exact SI relationships. Calculator logic and examples were reviewed by the DIY Cost Tools editorial team on September 28, 2026.
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