Macros · 6 min read
How Much Protein Do You Actually Need? (Grams per Kg by Goal)
Protein is the macro most worth getting right: it protects muscle while you diet, keeps you full, and has the highest thermic effect of the three. The official minimum (0.8 g/kg) is set to prevent deficiency, not to help you build or keep muscle. If you train, you want more. Here is how much, by goal.
The short answer
For active people who want to keep or build muscle, the research converges on roughly 1.6 to 2.2 grams of protein per kilogram of body weight per day. A landmark 2018 meta-analysis found that muscle gains kept improving as protein rose to about 1.6 g/kg and saw little extra benefit beyond that for the average trainee. The higher end (up to ~2.2 g/kg) is most useful when you are in a calorie deficit.
Worked example. An 80 kg person:
Maintenance or general training: 80 x 1.6 = 128 g/day.
Active fat-loss phase: 80 x 2.2 = 176 g/day.
Why you need more protein while cutting
When you eat below maintenance, your body is more likely to break down muscle for energy. Eating more protein (toward the top of the range) plus doing resistance training is the proven combination that tells your body to keep muscle and burn fat instead. This is exactly why our calculator sets protein first, before splitting the rest of your calories between fats and carbs.
Should you use body weight or lean mass?
For most people, total body weight is fine and simpler. If you carry a lot of fat, basing the target on body weight can overshoot, so using your lean body mass (or your goal weight) is more accurate. If you know your body-fat percentage, our body-fat estimator gives you the lean mass figure to use.
How to split it across the day
Total daily protein matters most, but distribution helps a little. A practical approach is three to four meals of 0.4 g/kg each, which for our 80 kg example is roughly 30 to 40 g per meal. You do not need to obsess over a 30-minute post-workout window; getting your total over the day, in a few solid servings, is what counts.
Special cases
- Older adults respond a little less efficiently to protein, so the upper end of the range plus resistance training is sensible.
- Plant-based eaters can absolutely hit these numbers; lean on soy, legumes, seitan and a quality blended powder, and aim slightly higher since some plant proteins are less complete.
Enter your stats and goal; the calculator sets a protein target in this range first, then fills in fats and carbs.
Set your protein and macros →Frequently asked questions
Is 1 gram per pound the same thing?
Roughly, yes. 1 g per pound is about 2.2 g/kg, which sits at the top of the evidence-based range. It is a fine target during a cut and a reasonable (if slightly generous) one otherwise.
Can too much protein harm healthy kidneys?
In people with healthy kidneys, higher-protein diets in this range have not been shown to cause harm in the research. People with existing kidney disease should follow medical advice.
Do I need protein right after my workout?
The anabolic window is much wider than once believed. Hitting your total daily protein across a few meals matters far more than timing a shake within minutes of training.
How is protein different from calories?
Protein is one of the three macronutrients that make up your calories (4 kcal per gram). You can hit a calorie target many ways; setting protein first ensures the muscle-protecting macro is covered before the rest.
References
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength. Br J Sports Med. 2018;52(6):376-384. doi:10.1136/bjsports-2017-097608
- Phillips SM, Van Loon LJC. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci. 2011;29(sup1):S29-S38. doi:10.1080/02640414.2011.619204
- Helms ER, et al. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20. doi:10.1186/1550-2783-11-20