Three calculators gave me three different protein targets for the same numbers — which one do I use?

I ran roughly 1.2g per kilo for twelve weeks and then roughly 1.6 for twelve weeks with the same programme and the same calories, and logged everything. Strength went up in both blocks and the difference in the rate was not large enough for me to be confident it was real. What did change measurably was hunger: at the higher protein I was noticeably less hungry in the evenings and my calories were easier to hold steady without trying. So my honest conclusion is that the higher number helped, but through appetite rather than through anything dramatic.

Mild heresy: protein target is the least important number in your post. You have been lifting a year, you are not in a rush, and the things that will determine your next twelve months are showing up three times a week, adding weight to the bar, and sleeping. I have watched people optimise from 100 to 140g of protein while running a programme they change every six weeks, and get nothing. Hit something reasonable, stop calculating, go and train.

I chased 200g for a while on the more is better logic and what actually happened is that the rest of my diet collapsed around it. I was eating chicken, powder and egg whites, my fibre was somewhere terrible, and I felt worse in a way that took me a month to connect to my food. Higher protein has to displace something, and I would rather it displaced snacks than vegetables.

The spread makes sense once you know what each number is for. The lowest one is close to the general population recommendation of around 0.8g per kilo, which is set to prevent deficiency, not to support training, and it is a floor rather than a target. The highest is someone applying a bodybuilding rule of thumb per pound of bodyweight, which is why it looks so aggressive. The number that keeps turning up in the meta analyses of resistance training is a point of diminishing returns somewhere near 1.6g per kilo, which for you is about 125g, and that is the middle answer. If you have kidney problems or are pregnant, that is a conversation with a dietitian rather than a calculator.

Take 1.6 per kilo, round it to 125, spread it across three meals, and close the calculator tabs. The precision you are chasing is smaller than your daily logging error.