I found a few other calculators, but they wanted to know exactly how much exercise per day, BMI ration and so on. I suppose they might give a more exact estimate, but I figure this is close enough.

I've always gone by under 20 net carbs and twice as much fat as protein. This calculator gave about the same for losing weight, and allows more carbs for maintaining.

I don't plan on changing. I'll blow ketosis on Christmas dinner. My kid sister is making my mother's recipe for cavatelli. Italian comfort food.

Blowing ketosis once or twice a year isn't really a bad thing. I'll gain a pound, a few days later when I'm back in Ketosis, it'll go away.

My relative was taking advice from a gym trainer, who said under 50 carbs a day meant you are in ketosis.

Me? I wouldn't take any scientific advice from a gym trainer.