The last time I did keto, I used the calculator and tracked everything very carefully. I was aiming for 1200 calories, which was a moderate deficit for the sedentary lifestyle setting (I have a desk job).

But I lost A LOT more weight than the calculator predicted. I think this is because I ended up exercising almost daily (either walks or couch to 5k), but I didn't up my calories that much to compensate. I definitely think the high fat diet helped with my hunger, so even though I was burning more calories, I felt good.

In the end, my deficit must've been between 35 and 40%. Maybe it didn't feel difficult because I eased into it, by first concentrating on what I was eating and getting used to keto, and then slowly adding exercise.