Protein Calculator

Why protein needs vary so much

The protein figure printed on food labels and in public guidelines, 0.8 g per kg of body weight, is the amount that prevents deficiency in sedentary adults. It was never meant to be the best intake for someone lifting four days a week and trying to build muscle or hold on to it in a diet.

Training increases how much protein your body uses to repair and build muscle. A calorie deficit increases it again, because your body is more willing to break muscle down for energy. That is why this calculator asks for your goal, not just your weight.

How to use the calculator

Enter your body weight in kg or lb and choose the goal that fits you best. You get a daily range in grams, an amount to aim for at each of four meals, and food equivalents so the number feels real.

The maths

Daily protein (g) = body weight (kg) x grams per kg

Per meal (g) = body weight (kg) x 0.4

For a 75 kg (165 lb) person building muscle, that is 120 to 165 g a day, or about 30 g per meal across four meals.

The per-meal figure comes from research suggesting that spreading roughly 0.4 g/kg over at least four meals is a practical way to maximise muscle building across the day.

What the research says

A 2018 meta-analysis by Morton and colleagues in the British Journal of Sports Medicine pooled 49 studies on protein and resistance training. Gains in muscle levelled off at around 1.6 g per kg a day on average, with the upper confidence limit around 2.2 g/kg. That is why the build muscle range runs from 1.6 to 2.2.

The International Society of Sports Nutrition position stand (Jäger et al., 2017) recommends 1.4 to 2.0 g/kg for most exercising people, and notes that higher intakes may help preserve lean mass during a calorie deficit. Hence the higher fat loss range.

More than 2.2 to 2.4 g/kg is not harmful for healthy people but offers little extra benefit and crowds out carbs and fats that fuel training.

Turning grams into food

These are approximate protein contents for common foods:

Plant proteins are slightly less digestible and lower in leucine on average. If you eat mostly plant foods, aim for the top half of your range and mix sources.

Limitations and caution

If you carry a lot of body fat, calculating protein from total weight gives a figure that is higher than you need. Using your goal weight or lean body mass, from the lean body mass calculator, keeps it realistic.

Pregnancy, breastfeeding and older age change protein needs too. Adults over 60 generally benefit from the higher end of each range to counter age-related muscle loss.

Timing and distribution

Total daily protein matters most. Once that is covered, spreading it fairly evenly gives a small additional benefit. A study by Areta and colleagues found that four meals of about 20 g each stimulated muscle protein synthesis more over 12 hours than two large meals or eight small ones.

In practice that means building three to five meals around a decent protein source rather than eating most of it at dinner. Breakfast is where most people fall short; eggs, yogurt or a shake fix that quickly.

The window after training is less urgent than once believed. If you ate a protein-rich meal a few hours before lifting, there is no need to rush a shake afterwards. If you train fasted first thing in the morning, eating protein reasonably soon after makes more sense.

A serving of protein before bed, such as cottage cheese or a casein shake, is a convenient way to add another feeding for people who struggle to hit their total during the day.

Next steps

Fit your protein into a full plan with the macro calculator, then read how much protein to build muscle for timing and source tips. If you are dieting, body recomposition explains how high protein lets you lose fat and gain muscle at the same time.