I get different numbers depending on where I look, so yeah, all these calculators just give an estimate. But they help you figure out where to begin (also people on this forum help a lot; I went by others' experiences when I was deciding). Then you can adjust later depending on your results.
FYI, we are the same height and ~ same weight and I chose 1400 calories for losing weight. I exercise at least 4 hours/week, trying to ramp up to 7. When I actually count those 1400 calories AND exercise I do lose weight, slowly. But I had the mid-30s major metabolism shift so my pounds are hanging on for dear life. Hopefully you won't have that problem
You might want to look into calorie cycling as well. It's an option lower down on the freedieting page. Keeps things interesting and allows you higher-calorie days (but of course you have to do lower-calorie days as well, boo)