In the pursuit of knowledge, there are no dumb questions.

Inches are a measurement of the shortest distance between two points. Or in the case of measuring flower pots, its diameter. And a gallon is a measurement of volume. You can have a pot that is only 6" wide, but very tall, which can hold a large volume of soil. Or you can have a pot that is only 6" wide, but very short and flat, which can't hold very much soil at all. Both would still technically be 6" pots, but they would each hold a different volume of soil.

You can also have five gallon pots that are of different shapes; tall and narrow, or short and flat. They would have different sized diameters, but they would both still hold five gallons of soil within them.

This is pretty much everything that Dave has said already. I just thought I would elaborate.

All covered, and not dumb. With plastic pots you sometimes also see "Azalea Pots", which don't necessarily have to be planted with azaleas, but they are a lower pot so that a 6" azalea is lower and holds less soil than a normal 6" pot.

Agree, if you want to know something, the only way to find out is to ask.

The info so aptly provided already leads us to the realization that the phrase " __-inch pot" without other info or a pic means nothing. Your question is interesting to me because it caused me to realize that I have no idea what size any of my pots are, except a few that are small enough that their size is a novelty worth mentioning, and that I have zero curiosity regarding measuring any others.

What motivates you to ask about this? You may be spending time considering that which just doesn't matter.

...unless you're shopping for pots and want to make sure you're buying bigger ones. That just occurred. I've had a collection of pots for so long, I don't shop for pots when or because I repot & shuffle plants around to diff pots, I just raid my stash. Plastic pots are something I buy on impulse when on clearance. I've been buying unglazed clay pots lately, but not with a particular plant in mind, just hoping to get all smaller plants into those kinds of pots.

"What motivates you to ask about this?"

Nothing really in particular-I've just been going through plastic pots on Amazon labeled as "n-inch pot", so I just decided to ask yesterday when I had nothing to do :p

Thanks everyone! This has been really helpful :)

"I've had a collection of pots for so long"

Lucky you-I don't really have that many pots yet. Whenever the need comes up for a new pot I just go to Home Depot and find an appropriate sized pot :p

I'm planning to begin a pot collection hopefully this summer-I've already been collecting plastic cups and plastic take-out trays with the lids.

About that-I'm planning also to use a soldering iron to create holes in the pots for drainage/aeration (I'll do it outdoors). Do you all recommend a specific wattage to use?

Thanks again!

Sorry to disagree with the above (not with your question, which is not at all dumb :-)) but a 5G nursery pot does NOT hold 5 gallons of soil or any other material - these are called "trade sizing", are standardized throughout the nursery industry and the volume does not match the labeled sizing (don't ask for an explanation - too complicated to go into!). A 5G nursery container - your typical black nursery pot - holds approximately 3.8 gallons or .77 cubic feet.

Decorative containers - either plastic/resin, terra cotta or more fancy glazed ceramic - are not bound by these standardized rules so measurements and volumes will vary based on the shape and size of the pot.

FWIW, the best way to determine what any container will hold is to use a quart measuring jug to fill.

For the record, I wasn't referring to industry standardized pots. I was simply stating that pots that can hold five gallons of soil can be many different shapes, with many different diameters, and still hold five gallons of soil. I wasn't claiming that these five gallon industry standard pots hold five gallons of soil.

Excellent, GG. That info adds dimension to the previous posts, doesn't negate them, IMVHO. When I have a 5-gallon pot, I know it's 5 gallons because it's a bucket that's been repurposed from its' previous employment regarding its' volume. I'm using several of these.

But is really only the nursery trade pots that come labeled as 1G, 3G, 5G etc. The more decorative pots seldom come sized at all, or at best, with a top diameter measurement, nothing more. So the natural assumption is that if you are referring to a 5G container, it would be a nursery trade container. And those don't hold 5 gallons of anything ;-)

More helpful info. ;)