What the protein calculator does
Protein needs scale with body weight and activity. Enter your weight and choose a goal — sedentary, active, muscle building or athlete — and the calculator returns a daily protein target in grams, using intake factors drawn from dietary guidelines and sports-nutrition research. It gives you a number to plan meals around rather than a guess; it runs in your browser and stores nothing.
The factors used
| Goal | Grams per kg body weight | 70 kg (154 lb) person | Basis |
|---|---|---|---|
| Sedentary | 0.8 g/kg | 56 g | RDA — the minimum to prevent deficiency in healthy adults |
| Active | 1.2 g/kg | 84 g | Regular exercise, physically demanding job |
| Muscle building | 1.6 g/kg | 112 g | Meta-analyses find gains plateau around 1.6 g/kg |
| Athlete | 2.0 g/kg | 140 g | Heavy training, cutting phases, endurance + strength |
Daily protein (g) = body weight (kg) × factor
Pounds to kg: divide by 2.205 → 180 lb = 81.6 kg × 1.6 = 131 gWhy 0.8 g/kg is a floor, not a target
The RDA of 0.8 g/kg was set to prevent deficiency in nearly all healthy adults, not to optimise anything. Research since then consistently finds benefits above it for most people: better muscle retention while losing weight, better recovery from training, better appetite control, and — importantly for older adults — slower age-related muscle loss, with many geriatric guidelines recommending 1.0–1.2 g/kg for over-65s. Unless you are sedentary and eating plenty already, the “active” setting is a more realistic everyday target.
Spreading protein across the day
- Muscle protein synthesis responds best to roughly 0.3–0.4 g/kg per meal — 20–40 g for most adults — repeated three to five times a day. One huge dinner is less effective than the same total spread out.
- Include protein at breakfast; it is the meal most people under-eat it at.
- A protein-rich snack before bed (dairy is well studied) supports overnight recovery for people training hard.
- Timing around workouts matters less than daily total; the “anabolic window” is several hours wide.
What 30 g of protein looks like
| Food | Serving for ≈ 30 g |
|---|---|
| Chicken breast, cooked | 110 g (4 oz) |
| Salmon | 130 g |
| Lean beef, cooked | 115 g |
| Eggs | 5 large |
| Greek yogurt (10% protein) | 300 g |
| Cottage cheese | 270 g |
| Firm tofu | 350 g |
| Tempeh | 160 g |
| Cooked lentils | 330 g (1⅔ cups) |
| Whey protein powder | 35–40 g (one scoop) |
Adjustments the calculator does not make
- Very high body fat: factors are meant for lean mass; using total weight over-estimates. Use goal weight or an adjusted weight instead.
- Weight loss on a calorie deficit: aim for the higher end (1.6–2.4 g/kg) to preserve muscle.
- Pregnancy and breastfeeding: needs rise by roughly 0.2–0.3 g/kg; follow clinical advice.
- Kidney disease: protein may need to be restricted; this calculator is not appropriate — follow your nephrologist's guidance.
- Plant-based diets: aim slightly higher (about 10%) to offset lower digestibility, and combine sources across the day.