As noted by @PaulL if you let your body tell you when to eat and when to stop you won’t have to worry about this. Assuming your hunger and satiety signals are relatively normal. But if not, or you want to do it just for the sake of doing it or experimentation - here’s what I did when I started keto.
I had no idea what my BMR was or my TDEE. So I just assumed being a 71 year old - and moderately active - male my BMR was probably around 1500 kcals per day and my TDEE about 1800 kcals per day. I had about 25 pounds of fat I wanted to lose, so I thought eating 1500 kcals per day would be a conservative deficit and I’d lose it. Well, I certainly lost it! In about 3 months - and then some.
I started keto with a 4-day water fast. On day two I experienced what I term ‘carb hunger’. I describe it as like the flesh eating plant in the movie Little Shop of Horrors constantly demanding to be fed. By the morning of day three the carb hunger was gone and I have never felt hunger since. What I now experience as ‘hunger’ is just a gentle and fleeting reminder that I haven’t eaten for awhile and it might be a good idea to do so. I compare this ‘keto hunger’ to the accountant reporting at a monthly board meeting that outgo exceeded income during the preceding month and the difference had to be made up from the current account. Not exciting stuff.
After the first 3 months - and 25 pounds lighter - I decided I had lost as much weight/fat as I wanted and started eating more to eliminate the deficit. Stopping the loss took an additional 3 months, bumping up my total daily kcals every week or two, and losing another 10 pounds of fat in the process. At 2500 kcals per day my weight and body comp stabilized at 145 pounds and 14-15% BF. I have maintained the same for 4 years. These numbers approximate my body comp at the age of 18 - I’ll take it, thank you!
So I started keto eating at a 1000 kcal per day energy deficit and only stopped losing when I got to 2500 kcals per day. Was I a CICO Success Story™? I don’t want to get into that here, but very willing to elsewhere - and might. Eating very low carbs, moderate protein and high fat kept my insulin low, and my adipose cells wide open releasing the energy to make up the difference. And I never felt the slightest bit hungry doing it. In fact, I suspect that absence of hunger is a key component of this whole process. One is never free from hunger on a conventional CICO diet regimen. For me, at least, keto removed that completely.
A year later I got a full-time job at Walmart and started losing weight. I dropped to just a little less than 141 pounds. I had an idea what to do to stop it. I upped my kcals per day to 2700.
Yes, I weigh my food, eat to macros and a ‘caloric window’. As long as I do so I maintain my overall weight and body comp, have lots of energy and remain mentally alert and healthy. I do this because I do not have reliable hunger and satiety signals. I did all the decades eating SAD, but not now. Maybe they will come back - I don’t know. But I don’t find measuring and calculating tedious. I designed a spreadsheet that does most of the work planning my daily meals.
At 4 1/2 years of keto, I’m a happy camper.