Safe rate weight loss per week calculator?

I believe the guideline is 2 pounds OR 1% of your body weight. In reality it comes down to how much energy you use in a day - so some people can't actually lose 2 pounds a week.

Have you estimated your TDEE? That is, how much total you burn in a day (on average) due to bmr, normal daily activity, and cardio? If so that is your starting point. Then consider what calories in you can do, where you get enough nutrition and feel satiated/satisfied.

If your TDEE is 3500 because you're a 6' 300 pound guy with a BMR of 2300, you could probably do well on 2000 in per day and aim for 3 pounds per week.

But if your TDEE is 3500 because you're a 6' 240 pound buy with a BMR of 2000 who is training for a marathon, then 2000 a day would probably kill your training.

If you're female, you probably won't be able to achieve a TDEE of 3500...

I think a good rule of thumb is about 0.5% - 1% of your body weight per week, provided that the calorie deficit you create to achieve that weight loss still allows you to eat enough calories each day to meet your nutritional needs (BARE minimum of approximately 1200 for most women and 1500 for most men, though if you burn more per day your personal safe minimum may be much higher).

For example: 300lb man, burns about 3500 calories per day through daily activities and some light exercise. 1% of his body weight would be 3lbs/week, which requires a 1500 calorie per day deficit, such that he'd be eating about 2000 calories per day. At least to start out, this seems perfectly reasonable and achievable.

On the flip side, 150lb woman, burns about 1750 calories per day. 1% of her body weight would be 1.5lbs per week, which would require a 750 calorie/day deficit, which would leave her eating no more than 1000 calories per day. Not good. 0.5% of her body weight per week, or 0.75lbs, would be a much better choice - that's a 375 calorie/day deficit, or a 1375 calorie goal. Still kind of low, but if approached with care still totally doable.

Everyone is different. I think the maximum safe sustained weight loss for anyone not under the care of a doctor would be about 1% per week, but that's not going to be the max safe weight loss for every individual. It depends largely on your calories burned per day, what calorie minimum is appropriate for YOU based on your activity goals and how your body reacts to a deficit, and how close to goal you are.

I have no specific source for this other than many years of reading and learning here on the MFP boards and beyond.

ETA: I took a REALLY long time to type that, haha. At least I mostly agreed with the first post! Also, my 300lb guy also was 6 feet tall in my head, lol. Crazy weird how we came up with the same example, even ending up with the same calorie goal per day!