The age of the NWC

[Dumbledork]

We all know the age of these characters
16: Ranma, Akane, Ukyo
17: Nabiki, Tatewaki
19: Kasumi
But is the age of the others mentioned anywhere in the manga, anime or interviews with Rumiko Takahashi?
I'd especially like to know the age of Shampoo, Ryoga (I don't think it was mentioned anywhere that he and Ranma wre in the same grade but only that they went to the same school. So they may not be the same age), Kodachi, Tofu, Genma, Nodoka, Soun, Happosai and Cologne (in fandom the age of the two latter ones ranges anywhere between 100 and 300).

[Acey]

The anime states that Soun and Genma are in their early forties, but that was in the rather silly 'Case of the Missing Takoyaki'. I would be inclined to agree with this though as Soun and Genma look to be adults when they sign away a future daughter to the Chardins, which Soun wouldn't have done had Kasumi been born at the time. So I'd place that event at at least twenty years earlier.

[Knight of L-sama]

Kodachi's the same age as Ranma and Akane. She's Kunou younger sister but she's still attending High School which means she's a first year student like Ranma, Akane and Ukyo.
I don't know about Happosai and Cologne's actual age but they're the same approximate age at least judging by the Nanban Mirror story.
As for Ryoga that fact that he and Ranma attended the same school does at least put a constraint on Ryoga's age in the 14-18 range (maximum of two years younger or older than Ranma depending on which year Ranma completed before he left to China.

[Drawde]

If you go by the information given in the manga, Ranma and Ryoga went to highschool together, which would make Ryoga 16 also. I've been unable to get an answer on whether or not highschool was the correct school in the manga.

[Zwzn]

Wew only have Genma's word that Ranma's 16, and Ranma doesn't seem to remember his his past very well. Ranma might be older or younger then 16.

[antimatterenergy]

Dumbledork -
For most instances this is what the ages are considered:
16 - Akane, Ryoga, Ranma, Kodachi, Ukyo, Shampoo, Mouse, Gonsunki
17 - Nabiki, Tatewaki
19 - Kasumi
mid to late 20's - Tofu, Hinako
mid-forties - Soun, Genma, Ranma's mom, Principal Kuno
over a hundred Happosai, Cologne - anime over 300 since amount of time traveled backwards via nabbian mirror.
Now those are not absolutes since we really aren't told all that much about their ages. It is possible for Kodachi to be 15 and have just skipped a grade at some point or just is in the age bracket where she will turn 16 sometime during the school year, or Shampoo can be 18 since we have no evidence one way or another, It is possible for Ranma's mom to be in her 30's (marriage age when she could have had Ranma was 13 after all), or Genma to be in his fifties since martial arts could slow down the aging process some, Happosai can be 120 or 300 something considering there are magical items (mushrooms of aging, junsenkyo, rejuvenation potion) and techniques (whatever Happosai did to Hinako) that can alter age. Plus Happosai can somehow survive for years without food, water, air, and female undergarments so him being positively ancient is not impossible heck he may have slept for a century like some mythical dragons do. According to wikipedia: In the anime episode "Case of the Missing Takoyaki!", Happosai's age is given as being estimated at four-hundred and fifty (450) years old but that is most likely wrong. Though not impossible since he could have used something that made him younger prior to the time he met Cologne.
Drawde - In all likelyhood Ranma and Ryoga attended junior highschool (secondary school, chūgakkō) together since Ranma is a freshman at Furikan (Upper Secondary school, kōtōgakkō) and the school year only started a few weeks before Ranma started (Ranma would have complained a lot if he was repeating a year).
Zwzn - Ranma remembers his past just fine whenever he has/want's to. He demonstrated this by Remembering Ukyo, Remembering things that happened when with Ukyo, Remembering food's that Gemna stole from him, Remembering how to get to Ryoga's house, etc... Of course this matters little if Ranma was never actually told his birthday in the first place which is possible but unlikely and is just judging his age by the age of his classmates. While there is some leeway in Ranma's age (possible that he turned 16 some time after the start of the manga but before the mushrooms of aging arc is one possiblity); It is stated in the anime that he is 16, Ranma thinks he is 16 (as shown by the mushrooms of aging story arc) and pretty much every website/summary of Ranma that mentions his age says he is 16.

[Zwzn]

Zwzn - Ranma remembers his past just fine whenever he has/want's to. He demonstrated this by Remembering Ukyo, Remembering things that happened when with Ukyo, Remembering food's that Gemna stole from him, Remembering how to get to Ryoga's house, etc... Of course this matters little if Ranma was never actually told his birthday in the first place which is possible but unlikely and is just judging his age by the age of his classmates. While there is some leeway in Ranma's age (possible that he turned 16 some time after the start of the manga but before the mushrooms of aging arc is one possiblity); It is stated in the anime that he is 16, Ranma thinks he is 16 (as shown by the mushrooms of aging story arc) and pretty much every website/summary of Ranma that mentions his age says he is 16.

I disagree about his memory. He didn't even remember Ryoga after about a year. Personally I blame the table to the back of his head.

[antimatterenergy]

Why would Ranma remember Ryoga? Ryoga and Ranma were not friends in middle school. Ranma barely even noticed Ryoga when he took the bread (just used Ryoga's head as a spring board). While Ranma did have a running battle with Ryoga to and from school most days Ranma probably barely talked to Ryoga except to make fun of him. Also Ranma was able to remember Ryoga after he thought about it for awhile. Ranma's memory is not perfect but it is far from bad (actually it is pretty good he just doesn't have instantanious recall) and a lot of things had happened since the time Ranma was around Ryoga (Junsenkyo Curse, Dragon Whisker Curse, trip to and training in China, finding out you have a fiancee, geting aclimated in a new school, and being chased by Shampoo to name a few things).
How well would you remember someone you interacted with for a few times a day for a few months over a year ago after many stressful and more important things have happened? Example if you bumped into a teacher who subbed for a few months in one class over a year ago how quickly would you remember them?
Plus Ranma has demonstrated the ability to recall things that happened many years earlier such as remembering losing the Tendo dojo to the gambling king over 10 years earlier (which I think is pretty impressive after all how many specific events can you remember that happened 10 years ago not counting major life changing things like a death or wedding).

[Zwzn]

Why would Ranma remember Ryoga? Ryoga and Ranma were not friends in middle school. Ranma barely even noticed Ryoga when he took the bread (just used Ryoga's head as a spring board). While Ranma did have a running battle with Ryoga to and from school most days Ranma probably barely talked to Ryoga except to make fun of him. Also Ranma was able to remember Ryoga after he thought about it for awhile. Ranma's memory is not perfect but it is far from bad (actually it is pretty good he just doesn't have instantanious recall) and a lot of things had happened since the time Ranma was around Ryoga (Junsenkyo Curse, Dragon Whisker Curse, trip to and training in China, finding out you have a fiancee, geting aclimated in a new school, and being chased by Shampoo to name a few things).

How well would you remember someone you interacted with for a few times a day for a few months over a year ago after many stressful and more important things have happened? Example if you bumped into a teacher who subbed for a few months in one class over a year ago how quickly would you remember them?

Plus Ranma has demonstrated the ability to recall things that happened many years earlier such as remembering losing the Tendo dojo to the gambling king over 10 years earlier (which I think is pretty impressive after all how many specific events can you remember that happened 10 years ago not counting major life changing things like a death or your wedding).

Ranma doesn't seem to remember things until he is reminded of them. He seemed to consider Ryoga a friend to me.

[antimatterenergy]

Ranma doesn't seem to remember things until he is reminded of them. He seemed to consider Ryoga a friend to me.

That has nothing to do with Ranma's memory and everything to do with his mind set. Ranma is a live in the moment person who from what I can see doesn't want to remember his past (which from what we do know of his past makes lots of sense why would he want to recall things like Shampoo chasing him and the Neko-ken training?). It's not that he can't recall the past (we have seen him do so) it's that he generally doesn't want to.
As for considering Ryoga his friend, Ranma considers just about everyone to be his friend and someone who he fought with daily for awhile is more than enough for Ranma to consider that person a friend even if that other person considers him to be public enemy number 1 or that anyone else would only consider that person an aquantance at most. I would not at all be surprised if Ranma considered Kuno to be his friend.

[Tovath]

You know It could just be that Ranma is not good at placeing faces, I know I'm not. So he remebered Ryoga he just didn't reconize the guy attacking him as Ryoga right away