Raised Bed Soil Estimator

This raised bed soil estimator gives you everything you need to buy the right amount of soil — and know what it will cost before you get to the register. Enter your bed dimensions,…

All Shapes Supported Inches, Feet, CM & Meters Bag Count & Cost Estimate

Calculate Your Soil

Enter your raised bed dimensions below

Bed Shape
Measurement Units
Bag Size & Cost Options Optional

Raised Bed Soil Estimator

This raised bed soil estimator gives you everything you need to buy the right amount of soil — and know what it will cost before you get to the register. Enter your bed dimensions, add your bag size and price per bag in the optional fields, and instantly see your volume in every useful unit plus a precise cost estimate.

How to Use This Calculator

Select your bed shape (Rectangle, Square, or Circle), choose your unit of measurement, then enter your dimensions. For rectangular and square beds, enter length, width, and depth. For circular beds, enter the diameter and depth. Click Calculate Soil Needed to see your results instantly in cubic feet, cubic yards, liters, and gallons — plus bag counts for all four standard bag sizes.

Understanding Your Results

Cubic feet is the unit printed on most bagged soil at garden centers. Use this number to count bags. Cubic yards is the unit used by landscape bulk suppliers — divide cubic feet by 27 to get cubic yards. Liters is the metric equivalent (1 cu ft = 28.32 liters). Gallons is helpful for smaller container calculations (1 cu ft = 7.48 gallons).

Volume Formula (Rectangle)
Volume = Length × Width × Depth (all in feet)

Soil Mix Recommendation

The best all-purpose raised bed mix is 60% quality topsoil, 30% compost, and 10% perlite or coarse sand. This blend drains well, retains moisture, and provides the nutrients plants need. Avoid filling raised beds with pure topsoil — it compacts and restricts root growth. Always include at least 25–30% organic matter.

💡 Order 10% extra: Soil settles 10–15% after the first thorough watering. Buying a little extra prevents a second trip to the store.
Common Questions

Frequently Asked Questions

A 4×8 foot raised bed at the standard 12-inch depth requires 32 cubic feet of soil — about 1.19 cubic yards. You would need 32 one-cubic-foot bags or 16 two-cubic-foot bags. At an 18-inch depth you need 48 cubic feet, and at 24 inches you need 64 cubic feet. Use the calculator above to adjust for your specific depth.
The best all-purpose raised bed mix is: 60% topsoil, 30% compost, 10% perlite or coarse sand. For a premium option, try Mel's Mix: equal thirds of compost, peat moss (or coco coir), and coarse vermiculite. Avoid filling beds with pure topsoil — it compacts and drains poorly in a raised environment.
Filling a standard 4×8 bed at 12 inches deep (32 cubic feet) typically costs $100–$350 depending on soil quality. Budget bagged soil: roughly $100–$160. Premium bagged mix: $200–$350. Bulk delivery: $80–$150. Enter your price per bag into the cost section of the calculator above for an exact estimate.
For irregular shapes, break the bed into simple geometric sections (rectangles or triangles), calculate the volume of each section separately using this calculator, and add the totals together. For circles, select the Circle tab above and enter the diameter and depth. Most raised beds are rectangular — the Rectangle tab handles those perfectly.
Potting mix is engineered for containers: very light, fast-draining, and often lacking in nutrients for large volumes. Raised bed mix is specifically formulated for elevated garden beds — it balances drainage, water retention, and nutrition at the larger volumes raised beds require. Potting mix in a raised bed would dry out too quickly and cost significantly more per cubic foot.