Calculapedia

Potting Soil Calculator

How much potting mix do you need? Enter your pot size and how many.

Per pot
Dry quarts needed
Estimated cost
Shop potting mix →

How this calculator works

It treats each pot as a cylinder (diameter × height), totals the volume across all your pots, and converts it to cubic feet and dry quarts — the two ways potting mix is sold.

Worked example — three 12 in × 10 in pots:
π × 6² × 10 = 1,131 cu in ÷ 1,728 = 0.65 cu ft each → × 3 = 1.96 cubic feet (about 50 dry quarts).

Pots taper, so you’ll have a little extra

Most pots are narrower at the base than a true cylinder, so this estimate runs slightly high — which is good, since fresh mix settles and you’ll want a little reserve.

Frequently asked questions

How many quarts of soil for a 12-inch pot?

About 16–17 dry quarts for a standard 12 in × 10 in pot.

How do I convert cubic feet to quarts?

Multiply cubic feet by 25.7 to get dry quarts.

Planning a landscaping project

Measure each section separately when a bed or lawn is not a perfect rectangle, then add the sections together. Depth, moisture, compaction, and the way a supplier loads material can change the final quantity, so use the result as a purchasing estimate and confirm the supplier's coverage information.

How to use this estimate

Accuracy and limitations

Calculapedia provides educational planning estimates. It does not inspect your site, select products, guarantee quantities, or replace a contractor, engineer, architect, building official, or supplier. Confirm the final quantity and any safety or code requirements before buying or building.

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