Neither size is correct on its own. A 16mm die gives each face 256 square millimetres to work with, against 144 on a 12mm die, so the markings are easier to read. A 12mm die takes up a little over half the table space for the same pool. Which one suits you depends on how many dice you throw at once. Every die we make is 16mm; the 16mm dice range is where to start if that is the size you settle on.
Games Workshop sells both, which is the clearest sign that this is a preference rather than a standard. Its general Warhammer Dice set is twenty D6s measuring 12mm along each edge, while the Warhammer: The Old World set is twenty dice at 16mm.
Want to see the difference in space? Set a pool size below.
16mm
12mm
Choose a pool size, then compare.
The two blocks are drawn in proportion to each other, not at life size, so do not measure your screen. The figures assume dice packed edge to edge with no gaps.
What Do the Two Sizes Actually Measure?
Both numbers describe the length of one edge, which is why the gap sounds smaller than it is. Four millimetres is not much to say out loud.
Hold one of each and you are not really comparing edges, you are comparing lumps of resin, and the 16mm die is well over twice the material. On the table you notice something else again, because each face has roughly 78% more room on it for pips, numbers or an engraved emblem. The same four millimetres shows up in two different places.
One thing worth checking before you compare listings. On a D6 the figure is the edge length, which is unambiguous because every edge is the same. On other shapes there is no single edge to quote, so makers measure across the die in different ways and the same number can describe noticeably different dice. If you are buying a mixed set, compare the D6s and treat the rest as approximate.
Which Size Is Easier to Read?
16mm, in most situations, because there is more face to look at. That extra room is also why engraved symbols and painted markings tend to appear on the larger size: a faction emblem needs space that a 12mm face does not really have.
The caveat is that size is not the only thing driving legibility. Contrast between the body and the markings does a lot of the work, and a well-painted 12mm die can read better than a dark 16mm one with unpainted engraving. Treat size as one factor rather than the whole answer.
Which Size Saves More Space?
12mm, and by a wider margin than the edge length suggests. Because area scales with the square, a block of 12mm dice covers a little over half the table of the same number at 16mm.
| Pool | 16mm block | 12mm block |
|---|---|---|
| 10 dice, five across | 80 × 32mm | 60 × 24mm |
| 20 dice, five across | 80 × 64mm | 60 × 48mm |
| Fitting a 100mm row | 6 dice | 8 dice |
On a crowded board with terrain, that difference is real. It matters most if you play games with large pools, roll into a small tray, or carry everything to a club in one bag.
Is One Size Fairer Than the Other?
No. Nothing about the edge length makes a die more or less balanced. Fairness comes from how evenly the material is distributed and how consistently the die is cut, not from whether it measures 12 or 16 millimetres.
A heavier die carries more momentum and tends to settle sooner once it stops climbing, which is a handling difference rather than a probability one. Some players prefer the way a larger die lands, others find it travels too far off a hard surface, and both are opinions about feel. If you want to check whether a specific die is balanced, that is a separate job with a separate method, and it applies to both sizes equally.
Which Games Suit Which Size?
The honest answer is that the rules almost never specify. What changes is how many dice land at once.
- Games with large attack pools favour 12mm, because you may be gathering and sorting thirty or more dice.
- Skirmish games with small pools give 16mm room to breathe, since you rarely have more than a handful on the table.
- Board games and card games often need only a few dice, so face size wins over footprint.
- Dice used as tokens or markers benefit from being larger and easier to identify among rolling dice.
If you are picking dice for a specific system, our sci-fi and fantasy wargame dice and our tabletop game dice are sorted by the games they suit rather than by size.
What Size Do We Make?
Every die we make for rolling is 16mm. That includes the odd shapes in our fantasy football sets, where the block dice, the D8 and the D16 sit alongside the D6s. We also make a small number of 20mm resin tokens with square corners, which carry order and status icons rather than pips and are meant to sit on the table rather than be thrown.
We settled on 16mm because engraved, hand-painted emblems need the face area, and because most of the games our customers play use modest pools. That is a design choice for what we make, not a claim that 12mm is worse. If you play something that puts forty dice on the table at once, the smaller size is a reasonable thing to want, and we do not currently offer it.
How Do You Choose?
Work backwards from the biggest handful you throw in a normal game, then from how you read them.
- Count the largest pool you roll regularly.
- If that number is comfortably over twenty, weigh space seriously.
- If it is under ten, face size and legibility matter more.
- Check whether you roll into a tray, and measure it.
- Look at contrast on the actual dice, not just the millimetres.
- If you already own one size and it works, there is no reason to switch.
Mixing sizes within one pool is worth avoiding for a different reason: the dice look different at a glance, so it is easy to lose track of which belong to which roll. That is a tidiness problem rather than a rules one.
Do You Need to Choose at All?
Not really. Plenty of players keep 12mm for big-pool games and something larger for skirmish games or as markers, and nothing stops you doing both.
Our best selling dice are all 16mm resin, engraved and hand-painted, and they suit the second half of that split. They are unofficial accessories and are not affiliated with, endorsed by or licensed by any game publisher.
The Short Version
16mm gives each face 78% more area, which is why engraved and painted designs live there. 12mm packs the same pool into a little over half the space and weighs less than half as much. Neither is fairer than the other. Choose by the size of the biggest handful you roll and by how clearly you can read it from your side of the table.
