Quick answer
Calculate soil volume for rectangular garden beds and raised beds using inside dimensions and fill depth. Use the working RenoMetric calculator below for the actual estimate, then use this page to check assumptions, package rounding and project-specific considerations.
Open the working Mulch calculator
Formula
Worked planning example
A raised bed with 8 × 4 ft inside dimensions filled 10 in deep needs about 26.7 ft³ before settling allowance.
Common uses
- Raised vegetable beds
- Flower beds
- Herb gardens
- Planter boxes
How to get a better estimate
Measure the actual project rather than relying on listing dimensions. For irregular spaces, split the surface into simple measurable sections and add the results. Use the exact product label for package coverage, yield, density or square-foot coverage whenever it is available.
Keep waste and package rounding as separate steps. Waste covers cuts, breakage, pattern matching and unavoidable offcuts. Package rounding reflects the fact that many materials are sold only in complete bags, boxes, bundles or cans.
Before you buy: this page is a planning guide, not a contractor quotation or structural design. Verify final quantities with the product manufacturer, supplier or installer when project conditions could materially change the result.
Garden Bed Soil Calculator FAQ
Should I use inside or outside bed dimensions?
Use the inside dimensions because wall thickness does not hold soil.
Can I mix compost and soil?
Yes. First estimate total fill volume, then divide that volume according to your chosen mix ratio.
Do I fill a raised bed to the very top?
Usually not. Leave the freeboard you want, and use the actual intended soil depth in the calculation.