Garden Soil Calculator

Work out how much soil your garden beds need, plan a custom mix, and estimate how many bags or how much bulk soil to buy.

Multiple beds Custom soil mixes Bag & bulk estimates

A better starting point

Measure inside the bed walls and use the depth you want to fill. You can adjust the estimate as you go.

updates as you type

Project type

Bed shape

measure inside the walls

1 of 20 beds

What are you filling? Fill the bed completely with new mix Some soil is already in the bed — I'm topping it up

Depth of existing soil Units

Fill percentage 50–100% — most people fill to about 1″ below the rim Settling / waste allowance 0–30% — extra for settling, spillage and paths

optional

Blend a custom 3-part mix (topsoil · compost · amendment)

Total 100% Topsoil % Compost % Amendment %

optional

Leave prices blank to skip cost estimates. Bags suit small jobs; bulk usually wins above ~1 yd³.

Bag size Custom bag (cu ft) Price per bag ($)

Bulk price per yd³ ($)

How this calculator works & assumptions

All dimensions are converted to feet first: inches ÷ 12, centimeters ÷ 30.48, meters × 3.28084.
Volume of each bed = length × width × depth. If soil is already in the bed, the existing depth is subtracted before the fill percentage is applied.
The settling / waste allowance (default 5%) is added on top, covering compaction after watering, spillage and wheelbarrow leftovers.
Conversions: 1 yd³ = 27 ft³ · 1 ft³ ≈ 7.48 US gallons ≈ 28.3 liters.
Bag counts are always rounded up to the next whole bag. Mix percentages must total exactly 100%.
Costs are simple multiplication of your local prices — this tool doesn't assume any particular price.
Real-world volume varies with compaction, moisture and bed construction, so order slightly up rather than down.