The physical size of my home's new hot water tank is 593 US liquid gallons. And it only holds 40 gallons of water. That's about 550 gallons of insulation!

How tall and wide is it?

22" dia. x 48" H.

It's a cylinder.

Hmmm...79 gallons based on a calculator. That makes far more sense!

I see now I had used a converter from mm^3 to gallons but that converter was wrong.

I asked because my napkin estimate had it as ten ft tall

That'll teach me to practice outside my scope.

Don't forget US and Imperial gallons are different

Aye. And we also have US wet and dry gallons. So if a 40 US wet gallons water tank contains 10 US dry gallons of sediment, what is its wet capacity?

Google is your best friend….

Think common volume measures … cubic feet

I just asked Google "if a 40 US wet gallons water tank contains 10 US dry gallons of sediment, what is its wet capacity?"

Google responded: "Who cares? It's time to replace your tank, you dumb shit!"

Snarky

40 gal -> cu ft
- vol of cylinder for tank in cu ft
—————————————-
Results in cu ft vol of tank which is not for holding water
Covert to your favorite units

But you knew that

Google says you should stick to firmware.

Good thing I don’t take everything Google (nor anything coming off the internet) at face value ….

You should hear what Alexa tells me to do when she's upset with me. And I've tried...but can't!

I’m sure you did