Protein Calculator
Find your daily protein target in grams and g/kg for fat loss, maintenance, or muscle gain. Free, no signup.
Refine (body fat — optional)
Pre-filled from your previous calculation — adjust if needed.
Aim for about 125 g of protein a day, split across 4 meals. The useful range runs from 111 to 139 g.
Target computed on your estimated lean mass — fat tissue doesn’t need feeding.
Track your protein automatically — start a free AFITPILOT trialOptional
Email me this target
We’ll send this recap plus a short guide to hitting your protein every day without overthinking it.
No spam. Unsubscribe in one click.
Free newsletter
Keep these numbers handy
Get our best training and nutrition breakdowns, plus new calculators first.
About this calculator
Protein need tracks body mass, not calorie intake — which is why a fixed percentage of your calories under-delivers protein exactly when you cut. The research consensus (ISSN; Morton et al. 2018) puts the muscle-building sweet spot at roughly 1.6–2.2 g per kg of bodyweight per day, with the upper end during a fat-loss phase, where extra protein protects lean mass and blunts hunger. We set your target inside that range based on your goal and training status. If you enter a body-fat percentage, the target is computed from lean mass instead of scale weight, which is more accurate at higher body-fat levels. Spreading protein across three to five meals of 0.3–0.4 g/kg each maximizes the muscle-building signal versus loading it all at once.
Sources
Range 1.6–2.2 g/kg/day (ISSN position stand; Morton et al., Br J Sports Med 2018). Upper end favored in a caloric deficit.
FAQs
Is more protein always better?
No. Benefits for muscle plateau above roughly 2.2 g/kg for most people; eating well beyond that mostly displaces other nutrients without extra muscle. The exception is an aggressive cut, where slightly higher intakes help preserve lean mass.
Should I use bodyweight or lean mass?
For lean and average individuals, bodyweight is fine. At higher body-fat levels, targeting grams per kg of lean mass avoids overshooting, since fat tissue doesn’t need feeding. Enter a body-fat percentage and we’ll switch automatically.
Does protein timing matter?
Total daily protein matters most. That said, spreading it across several meals of 0.3–0.4 g/kg each, rather than one large dose, gives a modest edge for muscle protein synthesis. Aim for protein at each main meal, including one within a few hours of training.