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).
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.