Daily Protein Intake Calculator

Most people who ask how much protein should I eat? get a single number back, and that number is usually wrong for their situation. A 55 kg woman on a calorie deficit and a 95 kg man building muscle do not share a target. The Daily Protein Intake Calculator takes your body weight, your goal and how active you are, and returns a range that comes from the published sports-nutrition literature, not a guess.

Five goals cover the common cases. Maintain weight uses the 0.8 g/kg adult RDA with room up to 1.2. Build muscle sits at 1.6–2.2 g/kg, the ISSN meta-analysis range. Fat loss pushes higher (1.8–2.4) because protein preserves lean mass in a deficit. Athlete covers both endurance and strength at 1.4–2.2, and Older adult lifts the floor to 1.0 g/kg per the PROT-AGE group. Your activity level then biases the target toward the low or high end of that range.

Worked Example: 80 kg, Building Muscle, Moderate

The page opens on 80 kg, Build muscle, male, moderate activity, four meals. That gives:

• Scientific range: 128–176 g/day (1.6–2.2 g/kg × 80 kg).
• Target: 144 g at 1.80 g/kg, which is exactly the mid-point. Moderate activity does not move it.
• Energy from protein: 576 kcal. Each of four meals: 36 g.
• Food guide: 465 g of chicken breast, 576 g of tuna, or 1,440 g of Greek yoghurt would each supply the full 144 g.

Load Sample moves on to a 65 kg female maintaining weight, then a 90 kg very-active athlete, then a 72 kg female on a fat-loss plan, then a 68 kg older adult.

How the Math Works Out Your Target

Each goal carries a three-number range in grams per kilogram: a minimum, a mid-point and a maximum. The mid-point is the scientific baseline. Your activity level biases around it by a fraction of half the range. Moderate adds nothing. Sedentary pulls the target down by half the range; Very active pushes it up by half the range. The result is clamped to the goal's published bounds, so activity never pushes the target outside the literature.

Weight in pounds is divided by 2.20462 before any per-kilogram number is shown, and the kg button converts the number you typed rather than just relabelling the unit. Grams are rounded to whole numbers. The food guide divides the target by each food's protein density (e.g. 31 g per 100 g for cooked chicken breast) to give the portion in grams that would supply the entire daily target from that single source.

When Not to Use This Calculator

Body weight below 25 kg is refused with “Body weight must be between 25 and 350 kg.” The ranges are drawn from healthy-adult populations. They do not apply to children, to anyone with chronic kidney disease, to pregnancy, or to post-bariatric-surgery patients, all of whom need clinical protein targets.