Somebody on every chess forum asks it weekly: how long until I'm good? The answers range from "six months" to "ten years" to "never, quit now," which is another way of saying the question needs sharpening. So let's sharpen it: how long does it take a typical adult, playing and studying a few hours a week, to reach milestones that most players would call good?
Realistic timelines, roughly
From true beginner to 800-level online play: a few months of regular games, mostly spent learning to stop hanging pieces. From 800 to 1200: typically six months to a couple of years; this band is almost entirely about tactics and blunder reduction. From 1200 to 1600: one to three more years, where openings, endgames, and planning start genuinely mattering. Beyond 1800: years, and the hours-per-week requirement climbs steeply. Getting to titled level as an adult starter is rare enough that you shouldn't build plans around it, and common enough that you shouldn't call it impossible.
Those ranges are wide because the variance between players is enormous, and the variance comes less from talent than most people think. It comes from HOW the hours are spent.
What actually speeds it up
The single biggest multiplier is closing the loop between playing and learning. A player who plays ten games and reviews none of them learns almost nothing from those hours; the same ten games with even five minutes of honest review each will surface the two or three mistakes that player makes over and over. Fixing a recurring mistake is worth more than a hundred games of unexamined blitz, because it improves every future game at once.
The rest of the recipe is unglamorous: mostly slower time controls while learning (you can't practice thinking without time to think), daily tactics in small doses, a tiny opening repertoire you understand instead of a big one you've memorized, and the basic endgames. Nothing exotic. The players who improve aren't doing secret training; they're doing boring things consistently.
The honest part
Chess improvement is slow for everyone, and plateaus are the normal state, not the exception. The rating graph of every improving player looks like a staircase viewed through static: months of flat, a jump, months of flat. If you need constant visible progress to stay motivated, chess will hurt you; if you can fall in love with the process, the game gives back indefinitely. There is no age cutoff on getting meaningfully, satisfyingly better.
Whatever your timeline turns out to be, it shortens the moment your mistakes stop being anonymous. Know your two or three recurring failure modes by name and you're improving on purpose instead of by accident.