Pot Size Conversion Chart

How much soil do I need for my container?

Today was one of those days I wish there were something "standardized" about pot sizes. One catalog uses one set of measurements; another catalog uses something else. Stores use inches; nurseries use gallons. Ahhhh...

To add to the confusion, in the U.S., most nursery and garden centers use and sell pots by the inch or gallon, but in most of Europe, pot containers are sold by metric units, in centimeters or liters.

John Derrick
Published by: John C. Derrick
Editor / Founder
Pot sizes - inches to gallon conversion Image

Trying to figure out pot sizes is often quite a headache. You've got some in inches, some in gallons, and yes, even some in fluid ounces; the latter we're still trying to figure out. They do make this confusing, don't they? There's a theory going around that this purposely confusing system is a way for the mass market industry to charge more for plants, by the container size, not necessarily Plant Size!

While the volume of any given pot can vary based on its depth, width, and whether it is tapered or not, we've attempted to provide a rough guide below. Additionally, to determine the size of a pot, you'll typically measure across the top to determine the size (inches or centimeters).

Pot sizes - inches to gallon conversion Image

So let's try and break down these various sizes and measurements and set some general "accepted standards" for pot sizes. Please remember these are rough estimates and not a science. Some of the larger sizes especially are prone to variances in height, width, and depth of the pot. We've also attached a photograph that we hope will help allow you to visualize the differences.

Pot Size Conversion Chart

Inches to Gallons to Liters to Cubic Feet

Pot Sizes (inches)Pot Equivalent (U.S. Gallons)Dry Soil Needed (Approx. cu.ft.)
4" potpint / 0.5 quart / .125 gallon0.01 ft3
5-6" potquart / 0.25 gallon0.03 ft3
7-8" pot1 gallon0.13 ft3
8.5" pot2 gallon0.26 ft3
10" pot3 gallon0.40 ft3
11" pot4 gallon0.53 ft3
12" pot5 gallon0.66 ft3
13" pot6 gallon0.80 ft3
14" pot7 gallon0.94 ft3
16" pot10 gallon1.33 ft3
18" pot15 gallon2.00 ft3
21" pot20 gallon2.67 ft3
24" pot25 gallon3.34 ft3
30" pot30 gallon4.01 ft3
Pot Sizes (inches) International (Liters)
4" pot .5 L [.473]
5-6" pot 1 L [.946]
7-8" pot 4L [3.78]
8.5" pot 7.5 L [7.57]
10" pot 11 L [11.35]
11" pot 15 L [15.14]
12" pot 19 L [18.92]
13" pot 22.5 L [22.71]
14" pot 26.5 L [26.49]
16" pot 38 L [37.85]
18" pot 57 L [56.78]
21" pot 75.5 L [75.70]
24" pot 94.5 L [94.63]
30" pot 113.5 L [113.56]
Download Pot Sizes Conversion Chart

Download Pot Sizes Conversion Chart

Download the conversion chart in PDF format.

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Published/Updated on: 02-03-2024