I just turned fifty, and the only person who came even close to estimating my age was another trans man. He knew to add a few years. So far, nobody else thinks I've even hit forty.
But I can see the icy hand of age gripping me with its inexorable...uh, grip. In other words, I'm getting a bit gray at the temples, and I have a few wrinkles. Most are covered by the beard, though. I think that if I said I was forty, most people would believe me. They don't believe fifty.