Depends on how dedicated you are.
My example, I lost 30lbs in 2 months of IF. There is an upper limit on weight loss. I beleive it’s like 2 - 5 pounds a week. Doing the math, you could loose upto 20 pounds per month.
A lot of variables is underselling it a bit. Starting weight, body composition, deficit, fasting hours, etc.
It’s like asking how fast does ‘the’ car drive.
Me cutting out breakfast and some snacking is very different than say an older smaller person doing one meal a day. Folks are going to lose everything from functionally nothing to unhealthy amounts.