How Old is Captain America?

Steve Rogers was born in 1920. His body was frozen in the Atlantic Ocean in 1943 and thawed out originally in 1963 (I think with him being thawed out a time or two in the middle, it's a bit of a mess). Marvel uses an inconsistent rolling timeline with only occasional, conflicting references to age. I remember Peter Parker being 35, but I can't find that reference. The most recent time anchor I've seen (via Silk) is that Peter Parker was bitten 13 years ago.

This would make Rogers' body around 100 years old, conscious for 36 of them. It always annoyed me that he was treated as some kind of elder statesman when he was only 7 or 8 years older than Spider-Man.

This was roughly the case until the late 90s. I say roughly because he travelled backwards and forwards through time multiple times, usually returning at the point he left.  These trips were only a few days or weeks or the most.

In 1999, Captain America follows Korvak into the future around year 3000 - the scene opens with 3007, but we don't know how long he's been there. Korvak rules the universe with an iron fist, opposed by resistance efforts led by Captain America. Instead of killing Cap, Korvak reboots time, intent on crushing his spirit.

For the first 72 times, Cap doesn't remember prior timelines, and arguably these were just 72 time divergent Captain Americas. For following reboots Korvak allows him to keep his memories to rub his failure in his face. Not sure the mechanism for this, but I'm thinking he sent Cap's consciousness back in time at the beginning of each divergent path, each having more cumlative memories.

We're shown five of these futures, adding up to at least 78 years, but Cap later mentions it happened hundreds of times - he's either wrong, or we were only shown a select number of reboots.

Presumably he only kept the body from the last reboot, which adds at least 10 years to his body's age, but his mind is at least 78 years older, possibly thousands. While I always questioned him being the world's greatest tactician out of three years in World War II, I don't believe they ever reference his centuries of organizing an intergalactic rebellion.

When talking about the age of his body we need to address the number of times he's died, or at least had his body destroyed and recreated. Between the super soldier serum, the Beyonder, and proximity to the Cosmic Cube, his body has a complicated track record, growing old at least twice.

Then there's his "death", where he gets unstuck in time. I don't know what happened to his body or how he got it back and I can't be made to endure an Ed Brubaker storyline again.

Before one of these elderly periods he spent around 11 years in Armin Zola's Dimension Z, where time move slower.  And in Avengers Millennium, Cap is frozen between the prehistoric past and and unspecified point in the future. Hawkeye says 13 centuries but he got educated at the carnival, more like 130, or 13,000 years.

This brings us up to 2015, and since then the multiverse has been rascaled by Beyonders and he came out as a Nazi sleeper agent and who knows what else has been retconned since then.