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Raised Garden Bed Soil Calculator with Settling
Raised-bed soil volume is length × width × fill depth. Add a settling allowance because fresh mixes compress after watering. A bed does not always need soil to the full board height; leave headspace for mulch and irrigation, and avoid filling above untreated siding or trim.
Planning estimate only. Check measurements and real-world constraints before buying materials or making a commitment.
Calculate your scenario
Change any input. Results update immediately.
Your results
Finished soil volume
42.7 ft³
Volume at the target fill depth.
Volume to purchase
49.1 ft³
Includes settling allowance.
Bags needed
33
Using 1.50 ft³ bags.
How the calculation works
The calculator applies this relationship to the inputs above. Keep every measurement in the unit shown.
Worked example
Use this example to check the calculator by hand before relying on a result.
Assumptions behind the result
- • The bed is rectangular.
- • Dimensions are inside measurements.
- • Fill depth excludes mulch.
- • Settling occurs after filling and watering.
- • Existing soil or woody fill is excluded.
Mistakes that change the answer
- • Using outside bed dimensions.
- • Entering inches as feet.
- • Buying only the final compacted volume.