How the protein intake calculation works
The calculator starts with a goal-specific range in grams per kilogram of body weight. Maintenance uses 1.2–1.6 g/kg, fat loss uses 1.6–2.4 g/kg, and muscle gain uses 1.6–2.2 g/kg. Athlete-level training adds 0.2 g/kg to both ends. Age 50 or older raises the lower bound by 0.2 g/kg because preserving muscle becomes more important; it does not automatically raise the upper bound.
daily protein range = body weight (kg) × goal band (g/kg)
athlete: add 0.2 g/kg to both bounds
age 50+: add 0.2 g/kg to the lower bound
meal distribution anchor ≈ body weight (kg) × 0.4 g/kgThese bands are planning ranges, not a claim that the upper number always produces more muscle. Morton and colleagues found that gains from supplementation levelled off around 1.6 g/kg/day on average during resistance training, with uncertainty extending higher. A wider range is useful during energy restriction, when appetite, leanness, training load, and the size of the calorie deficit affect how much protein is practical.
Worked example
An active 70 kg adult maintaining weight receives 1.2–1.6 g/kg, or 84–112 grams per day. Selecting age 50+ raises the lower end to 1.4 g/kg, producing 98–112 grams. Selecting athlete adds 0.2 g/kg to both ends. For fat loss, an 80 kg athlete aged 50+ receives 2.0–2.6 g/kg, or 160–208 grams per day.
The per-meal line divides the daily range across three to five eating occasions and shows 0.4 g/kg as a useful distribution anchor. That number is not an absorption cap. Digestion continues beyond one meal; spreading protein mainly helps make the daily target practical and provides repeated opportunities for muscle-protein synthesis.
Protein by body weight and goal
| Weight | Maintain | Lose fat | Build muscle |
|---|---|---|---|
| 50 kg | 60–80 g | 80–120 g | 80–110 g |
| 60 kg | 72–96 g | 96–144 g | 96–132 g |
| 70 kg | 84–112 g | 112–168 g | 112–154 g |
| 80 kg | 96–128 g | 128–192 g | 128–176 g |
| 90 kg | 108–144 g | 144–216 g | 144–198 g |
| 100 kg | 120–160 g | 160–240 g | 160–220 g |
| 120 kg | 144–192 g | 192–288 g | 192–264 g |
The table uses the base goal bands before athlete or age adjustments. People carrying substantial body fat may prefer to calculate from a medically agreed target weight, because multiplying current weight can overstate a useful intake. The TDEE calculator supplies calorie context; the days-between-dates calculator can define a consistent training or measurement block. For a separate risk-planning task, the position size calculator shows the same transparent-input approach.
Frequently asked questions
Can your body absorb only 30 grams of protein per meal?
No. Protein digestion and absorption continue beyond 30 grams. The practical question is how a meal contributes to daily intake and muscle-protein synthesis. Around 0.4 g/kg per meal across several meals is a useful distribution target, not a hard absorption ceiling.
Is a high-protein diet safe for the kidneys?
Research and sports-nutrition guidance generally support these ranges for healthy adults. Kidney disease changes protein handling and may require restriction or individual targets, so anyone with impaired kidney function, relevant medication, or a prescribed renal diet should use clinical advice instead.
Does protein timing matter for building muscle?
Total daily protein and progressive resistance training matter most. Distributing protein across three to five meals can make the target easier to reach and provide repeated high-quality servings. A protein-containing meal near training is convenient, but a narrow post-workout window is not required.
Should protein be based on current or goal body weight?
Current weight is a simple default for lean and moderately lean adults. If current weight is substantially above a healthy target, multiplying it can overstate needs; a clinician or dietitian may use goal weight, lean mass, or an adjusted weight instead.