Soil Calculator
Figure out exactly how much soil you need for your raised bed or pot, plus how many bags to buy. No math, no guessing, no leftover dirt taking up space in the garage.
Suggested Soil Mix (standard 1.5 cu ft bags)
How to Use This Soil Calculator
For raised beds: enter the inner length, width, and depth of your bed (for example, 8 feet long by 4 feet wide by 12 inches deep). Add more beds if you’re filling several at once, and the calculator will total the volume for you in cubic feet, cubic yards, and a suggested bag count for topsoil, compost, and sand.
For pots and planters: switch to Pot (Circular) mode and enter the diameter across the top of the pot along with its depth. Add multiple pots if you’re potting up several plants in one trip, and you’ll get the total volume plus how many standard bags of potting soil to pick up.
How Much Soil Do I Need?
The amount of soil you need depends entirely on the volume of your container or bed. A typical 4×8 foot raised bed at 12 inches deep needs around 32 cubic feet of soil, while a 10 inch pot only needs a fraction of a cubic foot. Rather than eyeballing it and ending up short (or with half a dozen leftover bags), this soil volume calculator does the math instantly so you know exactly what to buy before you head to the store.
Soil settles over time as it’s watered in, so it’s smart to fill your bed or pot slightly fuller than the bare minimum. Most gardeners round up rather than down.
Raised Bed vs. Potting Soil: What’s the Difference?
Raised bed soil is a heavier blend built for structure and drainage over a larger area, usually mixed from topsoil, compost, and sand. Potting soil is lighter and fluffier, designed specifically for the confined space of a container so roots get enough air and drainage. Using straight garden soil in a pot tends to compact and suffocate roots, so it’s worth using the right mix for the right space.
Frequently Asked Questions
How many bags of soil do I need for my raised bed?
It depends on your bed’s dimensions. Once you enter your measurements above, the calculator converts total cubic feet into a bag count based on standard 1.5 cubic foot bags, split across topsoil, compost, and sand.
How do I calculate soil volume for a pot?
Measure the diameter across the top of the pot and its depth, then use the Pot (Circular) mode above. The calculator handles the volume formula for you and converts it into quarts, liters, and cubic feet.
Can I use the same soil for raised beds and pots?
Not ideally. Raised bed soil is heavier and built for larger open spaces, while potting soil is lighter and formulated to drain well in a confined container. For the best results, use potting soil in pots and a raised bed mix (topsoil, compost, and sand) for garden beds.
Does this soil calculator work in cubic yards?
Yes. For raised beds, results are shown in cubic feet, cubic yards, and liters, so you can order bagged soil or bulk soil by the yard depending on the size of your project.