Ohhh, I have a lot of thought! In my little corner of the fandom, I age up all the characters.
Thoughts Under the Cut
America and Canada (as well as all the other nations in the Americas), I have at around 21. Young enough were there is an obvious age gap between them and the "old world" while being old enough to live their lives without restrictions in human society. Just a personal preference, but I personally headcanon there is no way America would stick with 18-19 as his age post WW2 or let congress /the president have so much control over him that he isn't able to drink in his own country. Government overreach!
In a human AU the ages shift by a few years. Sometimes I put them both closer to grad school age (23-24), but for the most past I write Alfred as someone who can easily pass as a Sophomore-Junior frat bro in college or as a college intern in the hill.
Ludwig is 21 in the modern day as well. However, he often can be mistaken for being several years older. His frequent worry lines, dilated eyes, hunching over, and dark circles age him.
Modern day, I view Arthur, Francis, Gilbert etc as being mid-40s.
I fully admit, I love me some major rusame age gap so I often imagine Ivan as not being that much younger then Arthur and Francis. Maybe a bit younger- late 30s- but often post WW1 has looked a lot older. Human AU, I truly am a sucker for college professor Ivan or mob boss Ivan. So he often is probably in his 40s in human AU. In either universe, Arthur is not thrilled his child's partner is practically his age.
Now the nations that have the biggest age jump in my head canons are Estonia and Liechtenstein.
Liechtenstein should at a minimum be the same age as America, in my opinion. The lands were "united" to become the country we know today in 1719. So I put her as 21 as well. She is petite and oftentimes very hyper girly, but that is a grown ass woman.
All the Baltics in my mind are late 30s. Estonia is also just kinda sort and bony.
AmePan moment where Kiku sees a portrait of Alfred during the late 18th or early 19th century, ie Alfred without glasses and with long hair, and is just. looks back at Alfred currently. looks at the portrait. realizes long-haired twink Alfred is 10000% his type and immediately starts making plans. the twink has turned into a twunk, that part can't be helped, but the long hair is definitely something that can be recovered and the glasses tend to get left on the nightstand for sex anyway.
Alfred is not so sure about the long hair but eventually decides to let Kiku have this for a little bit, but swears he is not keeping it long. Kiku makes a compelling counterargument by fucking him into next week, at which point Alfred concedes to keeping it just a few more weeks. this quickly becomes a cycle until some politician puts their foot down and demands Alfred cut his hair and stop looking like a hippie.
Matthew hates everything about this fyi. they already get mistaken for each other as it is and then Alfred goes and grows his hair out?? he complains about to Arthur, who pretty quickly (and against his will) becomes wise to what's actually happening. he suggests to Kiku they just use a wig and then he and Kiku pretend to forget they ever had the conversation.
Canada has negative rizz. Absolute boygirlfailure. A miserable scrap of laminate flooring. But what he lacks in charisma, he makes up for in helpfulness. He's the nation equivalent of borax: white as hell, affordable, multipurpose, and toxic when ingested
🎉 Happy Birthday to @kaunastika-the-sweetheart ! 🎉 Some CanLiet for thee!
Featuring Liet asking for a cheese from Canada’s poutine, a light hearted and silly doodle
The file for my original gift got corrupted 🥺 (it was a Nyotalia CanLiet drawing), so hopefully this will suffice while I redo it (which may take a while 😭)