The amount of protein you need to eat every day depends on a lot of factors like how much you weigh, and how much muscle you have – not just whether you’re male or female.

Calorie needs differ from person to person, so why not protein? After all, people come in all different sizes, and their body composition is highly variable – it stands to reason that protein needs could vary a lot, too. It doesn’t seem right that a 220lb (100kg) guy who works in construction and is into bodybuilding would have the same protein needs as a 150lb (68kg), male bank worker who sits down most of the day and spends his evenings on the couch.

Since protein is so important in maintaining your lean body mass (basically, everything in your body that isn’t fat), the suggested amount of protein you should eat every day depends, in part, on how much lean mass you have. Ideally, you’d get a body composition measurement done (some home bathroom scales even do this for you) which would tell you how much lean body mass you have. Then, you can easily determine amount of protein suggested for you, which is 1-2 grams of protein per pound of lean body mass (or, about 2-3 grams of protein per kilogram of lean body mass).

You can estimate your protein needs even if you don’t have scales with body composition analysis, based on your current body weight. It’s not a perfect method – it doesn’t take into account how much muscle mass you have – but it does at least account for differences in body size.

    Here’s how to calculate your protein needs:

  • Pounds: Multiply your body weight by 0.7
  • Kilograms: Multiply your body weight by 1.5

The number you get is a reasonable target for the amount of protein, in grams, that you should eat each day.

So, a woman who weighs 140lbs (64kg) should aim for about 100grams of protein a day; a 220lb man (110kg) should try to eat at least 150grams of protein.