Where are weights and heights defined by size class?

[Silpharon]

I see in the DMG chapter 8 a table with sizes (tiny, small, medium, etc) corresponding to square coverage on a board, but is there not a table that gives height/weight ranges for these size classes as well? If so, where is it in the books?

There are some tables online, but I don't see a 5e reference.

[PhoenixPhyre]

I see in the DMG chapter 8 a table with sizes (tiny, small, medium, etc) corresponding to square coverage on a board, but is there not a table that gives height/weight ranges for these size classes as well? If so, where is it in the books?

There are some tables online, but I don't see a 5e reference.

There's not one. For good reason--it's not well defined. On either axis. And there's heavy overlap, especially in the small-large range.

[Silpharon]

There's not one. For good reason--it's not well defined. On either axis. And there's heavy overlap, especially in the small-large range.

Interesting, ok thanks. It makes it hard to define the size of creatures/objects like Familiars, Homunculus Servants, Eldritch Cannons, etc (all potentially tiny, which is undefined it seems).

[JNAProductions]

Interesting, ok thanks. It makes it hard to define the size of creatures/objects like Familiars, Homunculus Servants, Eldritch Cannons, etc (all potentially tiny, which is undefined it seems).

The main issue is smaller than Small and bigger than Huge.

Since that covers everything from housecats to flies (on the small end) and hills to mountains (if they were creatures, on the big end).

I will say, though, weight would be basically useless-an Earth Elemental and an Air Elemental are the same size category, but one is heavier than many bigger creatures, while the other likely weighs less than a cat.

[Silpharon]

The main issue is smaller than Small and bigger than Huge.

Since that covers everything from housecats to flies (on the small end) and hills to mountains (if they were creatures, on the big end).

I will say, though, weight would be basically useless-an Earth Elemental and an Air Elemental are the same size category, but one is heavier than many bigger creatures, while the other likely weighs less than a cat.

Agree on both points. So it's presently allowable for an Eldritch Cannon or Owl Familiar to be the size of a ball bearing, unless the DM rules against it (understandably).

[Greywander]

A creature's size defines how much space they take up, but it's only really defined on a 2D plane. Space occupied is given in squares, not cubes.

I think for a good rule of thumb is that non-upright creatures (e.g. quadrupeds) should never exceed the length of one side of the space they occupy, e.g. a Large quadruped would never be longer than 10 feet. Though I think this rule tends to fail for exceedingly long creatures, such as snakes.

For upright creatures, like humans, height will fall between the length of one side of their current size and the length of one size of the next size up, e.g. a Large humanoid would be between 10 and 15 feet tall, roughly. You could also think about using the diagonal of the space as a guide for typical height, though for math reasons this will often be pretty close to the upper bound (the exception being for Medium).

I mention this almost any time the topic of sizes come up, but the 5e size system has two oddities. The way most sizes work out is that each step up is a √2 increase in size, but there are two exceptions. One is Small, which should be ~3.5 feet, but I'm pretty sure it just rounds up to 5 feet since you can't fit more than one Small creature in a 5 foot square. The other is Large, which is double the size of Medium. This means that there's a missing size between Medium and Large. Again, this missing size was probably dropped because it would need to round up to occupying a 10 foot square. It's unfortunate, because I feel like it could have been a good candidate for being a PC-accessible size, e.g. for goliaths and centaurs, allowing players to play a larger character without going all the way up to Large. The way it is now, we're somehow supposed to believe that a goliath or centaur is the same size as a dwarf.

[PhoenixPhyre]

Size category has very little to do with actual size, to the point where the gelatinous cube has a special feature to say it takes up its entire space. Size category is space controlled in combat, effectively "how tight can you pack the creatures and still have them able to act normally". That's all. This is especially true as you move away from Medium size.

Tails, wings, and other appendages don't fit in that space at all.