Measurments of Standard Polyhedral Dice

Hi. I am looking for the exact height and width measurements of standard polyhedral (D&D) dice in millimeters.

People refer to them as standard 16mm dice but I am not sure what that really means in this context. Is that the height of the d6?

I found this chart but I am not sure how accurate it is: The d6 and d12 look small to me.

My ruler sucks and I don’t have calipers to measure with, so a precise answer would be appreciated.


I don’t think that there really IS an industry wide standard. Certainly the dice that I see for sale come in all sizes, from itty bitty to humongous. I was at my local gaming and comic store the day before yesterday, and I didn’t notice any standardization in sizes.

The d6 would be the easiest die to measure, I would think, since it’s square in all directions.

The size definitely varies from manufacturer to manufacturer, and even the “official” D&D dice aren’t perfectly consistant.

If you’re looking for dimensions, you might want to try contacting one of the major manufacturers, like Chessex.

There used to be a company that specialized in “reference quality” poly dice; they advertised that their manufacturing tolerances were the tightest and that their dice randomized more evenly than most. I can’t locate them online, though; can’t remember the name.

Yup. Take a look at this page on Chessex’s web site; 16mm is specifically referring to the size of a d6.

To echo the other posters, there really aren’t industry standards. Chessex and Crystal Caste (two of the big U.S. dice manufacturers) make dice that are pretty similar in size, but I wouldn’t be at all surprised if they are not identical.

A manufacturer might be willing to share with you the exact sizes of their dice…but then again, they might not be. They may consider it to be proprietary information. Possibly worth contacting them.

Probably Gamescience; they’re still around.

This is perhaps not the best site (, but apparently even in Vegas, that is, for people who really care that the dice give random results, there is a variance in dice measurement of about 1/16 in (about 1.6 mm) for dice that hover around 3/4 in (19 mm), a variance of about 8 percent. So, there probably is no standard at all.

Why do want to know these measurements? Are you going to use them for something or this just for general knowledge?

Probably. Their dice have relatively sharp edges – not “you’ll cut yourself if you’re not careful” sharp, but not rounded off by tumbling (basically putting a bunch of dice into a drum and polishing them by repeatedly banging them around). The catch is that they generally have a little bit of flashing stuck on them from the initial molding, which can be ground flat with fine sandpaper.

I have a Gamescience d20 that’s been rolling around in my dice bag since the late 80s. The edges are still sharp, and the points are still pointy. Compared to most other dice of that era, the Gamescience dice were/are indestructible.

The newer dice (like Chessex) are made of a better plastic than were used for “first generation” polyhedrals, and I’ve never noticed an issue with wear on them. OTOH, most newer polyhedral / gamer dice tend to have rounded edges, as well.

Yep, Gamescience are definitely the ones I was thinking of. I don’t own any of their dice officially, but I own two sets of “unpolished,” sharp-edged dice that were, I think, branded Chessex but looked identical to the Gamescience ones. I own one set in clear and one in blue, both hand-painted. The clear-with-black-lettering ones are, in my opinion, the classiest polys I’ve ever seen. Look like props for an upscale 1920s fortune teller.