# Ceramic Coffee mug measurement

I have been looking for a coffee mug that will hold at least 12 oz of coffee. On ebay, I see things like mug is 3 1/2 inches across and 4 inches deep. This does not tell me a thing about how many ounces this cup will hold. Worse yet I do not know if these are inside or outside numbers, I've learned the hard way you cannot judge anything by the picture. So my question is: Can these figures be of any use in figuring out how many ounces a cup will hold?

• Why do you want a large ceramic cup? And this would probably be better on coffee.stackexchange.com – paparazzo Jul 24 '16 at 9:37
• Actually, some simple math should allow you to estimate the volume - if you have a cylindrical cup, it's height * radius^2 * pi. Assume the given vaules to be outside numbers, subtract an estimated wall thickness if you want to be more precise. – Stephie Jul 24 '16 at 11:10
• Shop locally; take 12 ounces of water with you in a bottle and visit your local potter, or take a measuring cup and even more water. If you want a big mug, ask, and they can make you one as big as you like. – Ecnerwal Jul 24 '16 at 12:40
• Honestly, it's a lot easier to search for the mug by ounces held (search: "mug 12 oz"), rather than look for mugs and try to estimate their capacity. When I was searching for a replacement for my own large mug, I added a couple ounces to my search, since some were measured as full to the brim and I usually don't fill mine quite that full. I got fewer results overall, but many more that were useful to my search (still some false results, though)... and I thought missing some that might have fit was better than wading through all of them that didn't. – Megha Sep 20 '16 at 9:30

I could derive the formula for you step by step, but I assume you didn't come here for a geometry lesson (if you want to learn the calculation, see https://www.mathsisfun.com/geometry/cylinder.html, and if you are stuck, you can ask questions on math.stackoverflow.com). So my suggestion is to head over to Wolfram alpha and ask. This is a site which tries to answer math problems given in human language. The query `volume of cylinder 3 inches across 3.75 inches high` returns 26.51 cubic inches. It has some conversions to other units, but not ounces. So we ask it a second query, `26.51 cubic inches in ounces` and it tells us that it is 14.69 fluid ounces.