Size Up

Onix is big, everybody knows that. But how big, next to you? Drag the silhouette to the size you think is right, lock it in, and watch the real Pokemon land right on top of your guess. All 649 Pokemon from Kanto to Unova are in here, from a 4 inch Joltik to a whale that is 47 feet 7 inches tall.

How Big Is a Pokemon, Really?

The Pokedex has always had the answer, it just prints it on a screen the size of a cracker, where 8 inches and 30 feet look exactly the same. Size Up fixes that by standing every Pokemon from Red and Blue through Black and White next to a full-size human, so you can see the number instead of reading it. Drag the slider (or use the arrow keys) until the silhouette looks right, lock it in, and the real Pokemon shows up as a green outline, around your guess if you went too small, inside it if you went too big. Humbling, honestly!

Your score is the smaller height divided by the bigger one, so guessing double and guessing half both score 50%, and only an exact match gets 100%. (That is the same as measuring how far off you were on a log scale, which is the fair way to compare a Joltik miss with a Wailord miss.) Each result becomes a block in your share line: a full block for 90% and up, dark shade for 75%, medium shade for 50%, and light shade for anything under that. The Daily is ten Pokemon, two from each region, the same ten for everyone on the same UTC date. Endless keeps dealing sets of ten from whichever region you pick, with a hot streak counter for every 90% round in a row.

The default human is 5 ft 6 in (168 cm). The CDC's FastStats page on body measurements reports US adults aged 20 and over, measured from August 2021 to August 2023, at 68.9 inches for men and 63.5 inches for women, and since it lists the two separately, the default adult stands at the halfway point, 66.2 inches. Put in your own height instead and the question changes from how big is Onix to how big is Onix next to YOU.

How Do Pokedex Heights Work?

Every Pokemon gets exactly one height in its Pokedex entry, and the original cartridges each stored it a little differently. I read them straight out of the disassemblies. The Japanese Pokemon Green stores one byte, the height in tenths of a metre, so Onix is 88 and prints as 8.8 m. The American Red and Blue store two bytes instead, feet and then inches (Onix is literally db 28,10), and the Pokedex prints them into a little HT ?′??″ template. Gold, Silver and Crystal pack both into one number, feet times 100 plus inches, so the same Onix is dw 2810. Three games, three storage formats, one very long rock snake.

Here is the Gen 1 quirk: every American height is just the Japanese metric figure converted and rounded to the nearest inch. I checked all 151 Kanto Pokemon against Green, and every one lands within half an inch of its metric value (the worst is 0.496 of an inch off, which is about as close to a coin flip as rounding gets). Because the originals move in 10 cm steps, lots of Pokemon share the exact same height, and the busiest height across all 649 is 0.6 m, which is 2 ft 0 in, with 62 Pokemon standing on it. The weights went through the same conversion and were rounded to the whole pound, even though the cartridge has room for tenths, which is why Pikachu weighs 13.0 lb in Red and Blue but 13.2 lb when you convert its 6.0 kg properly.

Gold, Silver and Crystal do not always agree, either. Entei is 6 ft 11 in in Gold but 6 ft 7 in in Silver and Crystal, and Tyranitar is 6 ft 11 in in Silver but 6 ft 7 in in Gold and Crystal. Size Up uses Red and Blue for Kanto and Crystal for Johto in feet and inches, and the metric figures from PokeAPI in metric mode, so Entei is 6 ft 7 in in one mode and 2.1 m in the other (Gold's 6 ft 11 in is the one that matches 2.1 m). Hoenn, Sinnoh and Unova have no cartridge disassembly to read from, so their heights are PokeAPI's metric values, converted to the nearest inch with the same rounding the Kanto figures follow. (And while we are on the subject of typos, Japanese Green lists Nidoqueen at 6.0 kg, and the disassembly marks that line with a plain "BUG, should be 600".)

Who Is the Tallest and Who Is the Smallest?

The tallest Pokemon from #1 to #649 is Wailord, at 14.5 m (47 ft 7 in). The smallest is Joltik at 0.1 m, which rounds to 4 inches, so Wailord is 145 times taller than Joltik. Right behind Joltik is an 8 inch club of nine: Diglett, Natu, Azurill, Budew, Burmy, Chingling, Shaymin, Foongus and Tynamo.

Look at how many of the giants are snakes! Five of the six tallest are measured head to tail. If you leave out the length rounds, the next after Wailord are Dialga at 17 ft 9 in and Lugia at 17 ft 1 in, and the tallest in each region is Lapras in Kanto (8 ft 2 in), Lugia in Johto, Wailord in Hoenn, Dialga in Sinnoh and Reshiram in Unova (10 ft 6 in). My favourite fact on the whole page: the Pokemon Yellow Pokedex says the tunnels Onix leaves behind "are used as homes by DIGLETTs." So the smallest Pokemon in Kanto lives inside the holes dug by the biggest one.

Why Do Some Rounds Say Length?

The Pokedex only has one number, labelled HT in the American games and たかさ (height) in Japanese Green, but for a Pokemon shaped like a snake that number is really its length, head to tail. The Game Boy games never say which ones, so I did not want to guess. From Diamond and Pearl onward the Pokedex sorts every species into body shapes, and as of Black and White its serpentine shape covers 24 of the first 649. (Bulbapedia's list of Pokemon by shape has today's list, and its table of changes shows eight of them moved in X and Y: Caterpie, Weedle, Wurmple, Burmy and Wormadam left the shape, and Shellos, Gastrodon and Cresselia joined it. PokeAPI's copy of the game data agrees with today's list.)

Fourteen of those 24 have long bodies that lie along the ground, coil up or swim: Ekans, Arbok, Onix, Gyarados, Dratini, Dragonair, Dunsparce, Steelix, Seviper, Milotic, Huntail, Gorebyss, Rayquaza and Serperior. Their rounds ask how long, not how tall. The other ten are caterpillars, cocoons, bagworms and slugs that rear up or hang upright in their sprites (Caterpie, Metapod, Weedle, Kakuna, Slugma, Magcargo, Pupitar, Wurmple, Burmy and Wormadam), so they stay height rounds. That part is a judgment call, and I would rather make it out loud than hide it.

The games' own text backs this up. Yellow says of Ekans that "the older it gets, the longer it grows," Gold says Dratini "steadily grows longer," and the categories read Snake, Cobra, Rock Snake, Land Snake, Iron Snake and Fang Snake. On a length round the silhouette is stretched so its top reaches the listed figure, which is the fairest picture a coiled sprite can give, so imagine the real one unrolled along the ground. Wailord, for the record, is filed as a fish, so its 47 ft 7 in is drawn as plain height. Big whale.

How Are the Silhouettes Scaled?

Every Pokemon is drawn with the front sprite from the game it debuted in: Red and Blue for Kanto, Gold for Johto, Emerald for Hoenn, Platinum for Sinnoh, and Black and White for Unova. For each sprite I measured the tight box around its opaque pixels, and the game scales that box so its height equals the Pokedex height at the scene's current scale, then paints every pixel in one ink colour. The pixels stay chunky on purpose (no smoothing), so a 28 foot Onix is drawn with Game Boy pixels the size of your thumb. The box includes whatever the sprite includes, like the mound of dirt around Diglett, so a few silhouettes are a touch generous.

The human is a plain figure I drew in SVG, 44 units wide by 100 tall, scaled to whatever height you set, and the ruler on the left rescales with it. When a guess towers over the human, the whole scene zooms out smoothly so both always fit (with reduced motion turned on in your system settings, it just snaps). When the real Pokemon is revealed you also get its sprite in colour: Red and Blue sprites wear their Super Game Boy palettes, Gold sprites their Game Boy Color palettes, and the newer games' sprites appear exactly as they are. After the tenth Pokemon all ten line up at true scale next to the human, and that is the same picture the Download button saves.

Your homework: set the human to your own height, then go find the Pokemon that looks you dead in the eye. If you have an idea for the next Pokemon data game, tell me about it, and if Gen 1 internals are your thing, the Glitchhouse has plenty more where these numbers came from.