How Long Does It Take To “fully” Recover From Total Knee Replacement Surgery?

From what I’ve observed it varies with each individual and other factors such as their weight, how active they were before surgery, if only one knee’s done at a time or it’s a bilateral (both knees at same time) surgery, and lastly but most important how determined you are to keep up with the physical therapy even on your own when you’ve finished your prescribed physical therapy.
Personally I had the bilateral knee replacement, am overweight, and only moderately active, so it took about 1 year for my complete recovery. The most encouraging thing to remember is that the pain one experiences after the surgery and pushing onward in your physical therapy is only temporary and will end, unlike the pain before the surgery.
Best wishes to you, or who ever you’re inquiring for.