How Many Pots Can You Fill with a Bag of Soil?

Find the size of your containers to determine the size of the bag you want to buy.

For example, a 20-quart bag fills two 12-inch standard clay pots, or you can fill one 14-inch basket and still have enough to fill half of another 14-inch basket. To follow this example, find the pot sizes in the column on the left, and then follow the line to the right to the shaded boxes.

Size of bag and approximate number of pots that it fills
Pot type & size	Approximate soil volume of pot*(dry quarts*)	10-qt bag	20-qt bag	32-qt bag	40-qt bag	64-qt bag
STANDARD CLAY POTS
8 ¼ inch	3.6	3	5½	9	11	18
10 ¼ inch	6.9	1½	3	4½	6	9
12 inch	10.7	1	2	3	4	6
14 inch	15.3	½	1¼	2	2½	4¼
STRAWBERRY JAR 5 gallon	14	¾	1½	2¼	3	4½
HANGING BASKETS
10 inch	5.5	2	3½	5¾	7	11½
12 inch	7.9	1¼	2½	4	5	8
14 inch	13.9	¾	1½	2¼	3	4½
BOWLS
8 inch	1.9	5	10½	17	21	34
10 inch	3.7	2½	5½	8½	11	17
12 inch	5.5	1¾	3½	3½	7¼	11½
14 inch	8.4	1¼	2½	3¾	4¾	7½
16 inch	12.0	¾	¾	2½	3¼	5¼
18 inch	18.8	½	1	1¾	2	3½
21 ¾ inch	31.2	¼	½	1	1¼	2
OVAL PLANTERS
12 inch	3.8	2½	5¼	8¼	10½	16¾
16 inch	7.3	1½	2¾	4½	5½	8¾
20 inch	9.4	1	2	3½	4¼	6¾
SQUARE PLANTERS
12 inch	11.2	1	¾	2¾	3½	5½
15 inch	23.0	½	1	1½	1¾	2¾
WINDOW BOXES
24 inch	11.7	1	1½	2¾	3½	5½
30 inch	15.6	½	1¼	2	2½	4
36 inch	19.7	½	1	1½	2	3¼

This isn’t perfect, but it beats a wild guess.

When you buy potting soil, are you just guessing at how much you need? We hope this table has given you a way to figure how much to buy. However,  these figures are approximate. Here’s why:

There are very few standards regarding container sizes and volumes. To make it even more confusing, containers that do list volume typically measure using liquid quarts. Of course, potting soil is not a liquid, so the bags contain dry quarts, which are about 1 1/8 liquid quarts. None of this is really important to your success. We’re just explaining so that you will understand why the numbers on this table are approximate.

Nor do these figures account for any packing down of the soil (the taller the container, the greater the compression). Compression can cause you to need 15% to 20% more soil. On the flip side, the soil that comes with your transplants (the roots) will add volume.

Do take notes about your own pots if you have containers that you use over and over again. That is the only way to know exactly how much to buy.

Store leftover soil in a dry place, perhaps in a clean plastic tub or garbage can, until next time.

Adapted from soil volume tables from Conrad Fafard, Inc., makers of commercial and home garden potting mixes.