I'd say probably four months, all though I still overestimate once in a while. It seems like some days I can eat more in a sitting than other days, and it's also variable based upon what kind of food I'm eating. Things that pack together well in my stomach allow for more intake, where things like salad require a smaller portion.

I second what GalgoMom said. I'm 2 1/2 years out and the amount I can eat still varies depending on what I am eating and sometimes it just varies day to day. I can eat more volume of soft foods (yogurts, soups) than solid protein such as meat. Solid protein sticks with me much better too.

I agree with the others, it varied with me and still does 15 months post op (it does get easier!). Don't think about trying to feel full (it'll be too late and you'll be coughing it all back up). Eat small bites, chew thoroughly, eat slowly. I'll repeat that for emphasis: eat slowly. Learn to stop eating when you're no longer hungry, not when you're full. The gift of WLS for me is that it's a tool that's thought me to understand what hungry is, and is not. Just because I "want" that donut doesn't mean I'm hungry.

I am 6 months out from sleeve. I still have difficulty stopping when I should. I know I've had enough, but with only 2 bites left I hate throwing out food I have paid for . Saving for later is an option too , just a bother.
Buying small bowls and plates helps me control portion sizes. I use my food scale occasionally .

Yep I felt the same on week three when I was able to begin to eat an egg. Now I am 8 weeks post op tomorrow and I am eating 2 oz of meat and maybe 1/4 cup of refried beans before I get my signal to stop. Almost every meal I have food that it put into the refrigerator for the next day. I also use the smallest plates I have and take tiny bites and chew like crazy. I am barely getting in 300 to 760 calories and 40 to 61 protein. I still have 1 protein drink a day as a meal replacement. Yet despite these numbers I haven't lost a single pound in 2 weeks.

With the sleeve, we still have our pyloric valve at the bottom of the stomach. Understanding how it works helps. Even when it's in the closed position it is open about the size of a pen tip. The less density the more open it is.

Broths and thin cream soups will keep the pyloric valve open and food basically seeps through. The more dense the more it closes. So with purees, the valve starts to close leaving the food in our stomachs, reducing the volume we can eat. With purees, it will still drip through that "closed" valve. As we switch over to solids, consuming proteins first will help get that baby closed as those are usually the densest.

Why we can eat more one day than another baffles the mind. I'm five months out and I still measure all my foods and there are days I can't finish, and others I feel like I could eat more.

I hope that makes sense and is helpful!

How? Weigh it, measure it, eat only that, and then stop. I had zero sensation of hunger or fullness for a while after surgery. If I'd just eaten, I could have hurt myself and stalled my progress. Instead, I measured exact portions (in grams), ate that very slowly, paid attention to how I felt during eating to learn the fullness cues, and ate nothing else. I followed the program to the letter and it really helped my success.