Protein is the most argued-about macronutrient on the internet, yet the science behind how much you need is surprisingly settled. Here is what the research actually says — and how to find your own number in about a minute.

The baseline: 0.8 g per kilogram

The Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kilogram of body weight per day. For a 70 kg (154 lb) person, that works out to about 56 grams a day. But there's a catch: the RDA is the minimum needed to avoid deficiency in a sedentary person — not the amount that's optimal for building muscle, losing fat, or aging well.

What active people actually need

If you exercise regularly, the evidence points considerably higher:

  • Recreational exercise: 1.0–1.2 g/kg per day

  • Building muscle (resistance training): 1.6–2.2 g/kg per day

  • Losing fat while keeping muscle: 1.8–2.4 g/kg per day

  • Endurance athletes: 1.2–1.6 g/kg per day

The often-quoted 1.6 g/kg figure comes from a large 2018 meta-analysis which found that muscle-building benefits plateau around that intake for most people.

Why protein matters more in a calorie deficit

When you eat fewer calories than you burn, your body doesn't just burn fat — it will happily break down muscle too. A higher protein intake protects lean mass during weight loss, and it's also the most satiating macronutrient, which makes sticking to a deficit easier. If you're cutting, aim for the top of the range rather than the bottom.

How to find your number

You don't need to guess. Our protein calculator gives you a personalized target based on your weight, activity level, and goal. Pair it with a TDEE calculator to know your daily calorie burn, and if you want the full breakdown — protein, carbs, and fat — the macro calculator will split your calories for you in seconds.

A quick rule of thumb if you don't want to do any math: eat about 1 gram of protein per pound of your goal body weight if you train, and you'll land inside the evidence-based range almost every time.

Can you eat too much protein?

For healthy people, intakes up to 2 g/kg (and even beyond) have repeatedly been shown to be safe. The "protein damages your kidneys" claim comes from studies on people with pre-existing kidney disease. That said, more isn't better past a point — protein above roughly 2.2 g/kg doesn't build extra muscle, it just replaces other foods you could be enjoying.

The bottom line

Sedentary? Around 0.8–1.0 g/kg keeps you covered. Training regularly? Aim for 1.6–2.2 g/kg, and lean higher when eating in a deficit. Start with your TDEE, pick a target, and spread your protein across three to four meals a day for the best results.