Landscaping & Outdoor
Topsoil Calculator
Plan a new garden bed, raised bed, or soil top-up with both bulk volume and whole-bag estimates.
- Raised-bed presets
- Bulk & bagged estimates
- Editable bag size
Enter your soil bed
Choose a common raised-bed preset or keep custom dimensions. Enter the finished soil depth and the volume printed on one bag.
Estimate result
How this estimate is calculated
The calculator uses the inside bed dimensions to find the soil volume and then adds your selected allowance. Raised-bed presets simply fill those same dimension fields.
Soil volume = bed length × bed width × soil depth × (1 + extra %)
Bag count uses the package volume you enter and rounds up. If an existing bed is partly full, enter only the depth that still needs new soil.
Topsoil Calculator FAQs
How much soil fills a 4 × 8 ft raised bed?
At 12 inches deep, the raw volume is 32 cubic feet, or about 1.19 cubic yards. With the default 10% allowance, that becomes about 1.30 cubic yards.
Should I use topsoil or garden soil?
Product blends differ. Use a soil recommended for the plants and bed type, and check whether the product is intended for in-ground use, raised beds, or containers.
Why add extra soil?
New soil can settle after watering and levelling. The adjustable allowance gives a planning buffer without hiding it in the formula.
Can I calculate only a top-up layer?
Yes. Enter the bed length and width, then use only the thickness of the new layer as the soil depth.
Suggested supplies
These non-affiliate Amazon search links can help you compare common project materials. Affiliate tracking can be enabled later from the shared site configuration.
Related project calculators
Continue planning with another calculator from the same BuildingMath site.