How do I use the Random Height and Weight table in the Player's Handbook to determine a creature's weight?

Question

I was reading through the Player's Handbook today to make a character when I saw the Random Height and Weight tables. Looking at that, I saw that the weight, for a Tiefling, was 110 lbs * (2d4). Surely, I thought, a 220-880 lb tiefling is a little bit much compared to their 4'11" - 6'1" height, so I looked at the others, and they are all similar.

Amusingly, the Mountain Dwarf has a weight of 130 lbs * (2D6), which can result in a character of the range of 260-1560 lbs, or close to a full ton of dwarf.

Has there ever been any clarification on this?

Answer 1

The table is poorly formatted, below is how to use it

The following is listed before the table:

If you want to, you can roll randomly for your character's height and weight using the Random Height and Weight table.

The dice roll given in the Height Modifier column determines the character's extra height (in inches) beyond the base height. That same number multiplied by the dice roll or quantity given in the Weight Modifier column determines the character's extra weight (in pounds) beyond the base weight.

- Player's Handbook (page 121, Chapter 4: Personality and Background - Character Details - Height and Weight)

Thus you do the following:

1. Roll the listed height modifier dice and add that total to your race's base height.
2. Multiply your height modifier roll by your weight modifier roll and add that total to your race's base weight.

The table is as follows:

$$ \begin{array}{|c|c|c|c|c|} \hline Race & Base\ Height & Height\ Modifier & Base\ Weight & Weight\ Modifier\\ \hline \hline \text{Human} & 4'8'' & +2d10 & 110\ lb. & \times(2d4)\ lb.\\ \hline \text{Dwarf, Hill} & 3'8'' & +2d4 & 115\ lb. & \times(2d6)\ lb.\\ \hline \text{Dwarf, Mountain} & 4' & +2d4 & 115\ lb. & \times(2d6)\ lb.\\ \hline \text{Elf, High} & 4'6'' & +2d10 & 90\ lb. & \times(1d4)\ lb.\\ \hline \text{Elf, Wood} & 4'6'' & +2d10 & 100\ lb. & \times(1d4)\ lb.\\ \hline \text{Elf, Drow} & 4'5'' & +2d6 & 75\ lb. & \times(1d6)\ lb.\\ \hline \text{Halfling} & 2'7'' & +2d4 & 35\ lb. & \times\ 1\ lb.\\ \hline \text{Dragonborn} & 5'6'' & +2d8 & 175\ lb. & \times(2d6)\ lb.\\ \hline \text{Gnome} & 2'11'' & +2d4 & 35\ lb. & \times\ 1\ lb.\\ \hline \text{Half-elf} & 4'9'' & +2d8 & 110\ lb. & \times(2d4)\ lb.\\ \hline \text{Half-orc} & 4'10'' & +2d10 & 140\ lb. & \times(2d6)\ lb.\\ \hline \text{Tiefling} & 4'9'' & +2d8 & 110\ lb. & \times(2d4)\ lb.\\ \hline \end{array} \\ $$

Let's say you're a Dragonborn, then you are 5'6" + 2d8 inches tall. You would roll those 2d8, and let's say you got 13, and were thus 6'7''.
Then you would also roll the Weight Modifier dice (2d6), and let's say you got 4. This means you would be 175+13*4 = 227 pounds.

Let's say you're a Gnome, then you are 2'11" + 2d4 inches tall. Let's say got a 7 and ended up being 3'6", then you would add 7*1 to your Base Weight landing you at 42 pounds.

Answer 2

The paragraph after the table in the PHB details the proper way to calculate weight.

This is well explained in Medix2's answer, but is a case outside of the PHB where the calculation is written differently that has not gotten clarification. In Guildmaster's Guide to Ravnica, the "Height and Weight" section on page 12 provides the calculation:

Height = Base Height + Height Modifier in inches

Weight = (Base Weight + Height Modifier in pounds) × Weight Modifier

While not being exactly the same as how you miscalculated it before, it has the same problem of weight scaling.

While not official, Jeremy Crawford tweeted out this, detailing that a character's weight calculation should be Base Weight + (Height Modifier in pounds × Weight Modifier).