hi
How hard is 1600 rating?

Sorry but your formula is not correct for chess elo points.
You are not considering that getting the highest elo rates in chess is exponentially more difficult the more you increase your rating. So, for example, the 200 elo points between 800-1000 points are more easy to achieve insead of 1000-1200 and so on.
Using your formula also means that if someone reach 2400 elo in (12-13k hours) can be a 4400 elo point in 24k hours! It doesnt work that way, unfortunately!
Lots of professianal chess players have spent so many hours to become IM, and probably the same ammount of hours to become GM. And also, some people, even if they study chess for their entire life, just cannot become GM (it depends on lots of factors... age and other things).
1600 elo points is a very easy reating to achieve. If you start as a child you can do it in just months or 1 year. Consider that IM Faustino Oro in just 2 years become IM, learning, playing and studyng 8 hours per day.
If you start as an adult you can achieve 1600 very soon, depending on how many hours you spend daily. It's very likely that in 1-5 years you can get it.
It took me 6 months to get 1600 (I am 16 yo) I was around 500 when I started playing (late Feb 2024) and hit 1600 on August, I gues the time can matter from person to person . ( THIS IS NOT MY MAIN ACC I HAVE NOT PLAYED ANY GAMES HERE MY MAIN ACC IS "Shikhar-Tripathi")

I started chess around 6 months ago and I'm around 1800 lichess(I never play chess.combecause of lag issues). Is this ok?

Just enjoy the game. Try to win each game. No bullet and blitz. It will be a long journey. Not unless you have a natural talent in chess; it would be fast.
I have written about the history of chess in my city. I know of two cases in which a player learned the moves as an adult and went on to play at an Expert level and compete for the state championship. One learned in his early 20s. The other learned in his mid-30s.
so, it is possible to learn to play as an adult and achieve at a high level.

You can definitely do it.
I don't want to mislead you into thinking it'll be easy, because it won't. If you want to reach 1600, you have to go through a lot of pain and suffering. It's by no means impossible, but if you want to get the number without the effort that comes with it, you're better off looking for something else.

Hey,
I just started to play chess and really got interested and want to know more about the game.
I wonder how hard and how long it will or could take to get to 1600 rating?
Im 21 and just wonder if its too late for me to get to this rating
With kind regards
I’m 12 and I’m 1600 in daily. It’s not that hard ig. All you have to do is: don’t give up.

Hey,
I just started to play chess and really got interested and want to know more about the game.
I wonder how hard and how long it will or could take to get to 1600 rating?
Im 21 and just wonder if its too late for me to get to this rating
With kind regards
I’m 12 and I’m 1600 in daily. It’s not that hard ig. All you have to do is: don’t give up.
Daily ELO doesn't mean anything

lmfao 6 months from scratch to 1600 is impossible

As a 32 year old ,playing since dec 2020, it took me 3 years to first hit 1600 online. I hit 1800 a little while ago (after about 4 years playing) for the first time until I lost focus and lost all the rating again.
My official OTB rating is higher, since I'm better at classical than I am at rapid. OTB I'm at 1740 fide right now after 1 year of playing tournaments and about 4 years after learning chess.
So yes, it is 100% possible to reach 1600!
As a 21-year-old, you should spend more time studying/reading than playing. Kids play lots of rapid and blitz games to get them motivated. However, you don’t learn very much from playing speed games against other beginners. So, study chess principles—openings, endings, middle game planning. As a motivated adult, you should be able to learn quickly and then be able to apply your learning in games.
several suggestions:
1. Analyze your losses. Don’t simply look at the game review, since that only shows individual moves and does not explain long-term plans.
2. Don’t try to memorize long opening sequences. Stick to general opening principles.
3. Play rapid or classical rather than blitz. Give yourself time to think.
4. Learn basic endgames. King and pawn endings. The principle of opposition. The strength of outside passed pawns. Rook activity.
as an adult, you can study and learn efficiently, so you will advance more rapidly than kids who are learning by trial and error from only playing blitz games.