You should bounce back fairly quickly if you go to a tournment or two. I've taken multiple huge breaks from chess, and an OTB wake up call is usually just what I need.
Shaking off the rust.
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It may take a while, and it also depends on what time controls you play (bullet, blitz, quick online, slower online, days per move). I haven't decided to go back to quicker games yet as I need to improve my tactical play as well as have more time to play say 30/G plus 5 sec. I like these kinds if games as you have enough time to even play out endgames. I probably also need to review more opening theory as I took a longer break and hadn't seriously studied any theory in maybe 8 years or more ( I was playing very infrequently for a while).
After a half-yer break from chess, how long does it typically take to get back to your original form/rating? I have been trying for a week and the progress is slower than I expected