How much protein you need
The Recommended Dietary Allowance — 0.8 g per kilogram of body weight per day — is the amount that prevents deficiency in nearly all healthy, sedentary adults: about 56 g for a 70 kg man and 46 g for a 57 kg woman. It is a floor, not an optimum. People who train, are losing weight, or are over 65 do better on more: sports nutrition bodies recommend 1.2–2.0 g/kg for active people, and studies of dieting athletes show muscle is best preserved at 1.8–2.4 g/kg. Intakes up to about 2.2 g/kg show no harm in healthy people; above that there is little additional benefit.
The table gives the targets for the example 77 kg (170 lb) adult.
| Goal | g per kg | Grams per day |
|---|---|---|
| General health (RDA) | 0.8 | 62 |
| Active adult | 1.2–1.6 | 93–123 |
| Endurance training | 1.2–1.4 | 93–108 |
| Strength / muscle gain | 1.6–2.2 | 123–170 |
| Fat loss, preserving muscle | 1.8–2.4 | 139–185 |
| Over 65 | 1.0–1.2 | 77–93 |
Protein by body weight
Targets scale with weight, which is why they are given per kilogram. For people with obesity, guidelines often base the figure on goal weight or an adjusted weight rather than current weight, since fat mass does not need protein the way lean mass does; the lean body mass calculator gives an alternative basis.
| Weight | RDA (0.8 g/kg) | Active (1.2–1.6) | Strength / cut (1.6–2.2) |
|---|---|---|---|
| 120 lb (54 kg) | 44 g | 65–87 g | 87–120 g |
| 140 lb (64 kg) | 51 g | 76–102 g | 102–140 g |
| 160 lb (73 kg) | 58 g | 87–116 g | 116–160 g |
| 180 lb (82 kg) | 65 g | 98–131 g | 131–180 g |
| 200 lb (91 kg) | 73 g | 109–145 g | 145–200 g |
| 220 lb (100 kg) | 80 g | 120–160 g | 160–220 g |
| 250 lb (113 kg) | 91 g | 136–181 g | 181–249 g |
Spreading protein through the day
Muscle protein synthesis responds to each meal's protein up to roughly 0.4 g/kg (25–40 g for most adults) and then plateaus for a few hours, so spreading the daily total across three to five meals uses it a little better than concentrating it. For a 135 g target, that is about 30–45 g per meal. The per-meal figure in the result reflects the number of meals you choose. Timing around training matters less than once thought; the daily total is what counts.
| Meal | Food | Protein |
|---|---|---|
| Breakfast | Greek yogurt 170 g + 2 eggs | 30 g |
| Lunch | Chicken breast 120 g + lentils ½ cup | 46 g |
| Snack | Cottage cheese ½ cup | 13 g |
| Dinner | Salmon 150 g + tofu 50 g | 46 g |
| Total | 135 g |
Protein in food
Animal foods and soy are 'complete' proteins with all essential amino acids in useful proportions; most plant proteins are lower in one or two, which a varied plant-based diet covers over the day. Protein density varies widely: chicken breast is about 31% protein by weight, Greek yogurt 10%, lentils 9%. The calculator shows how many servings of common foods make up your target.
| Food | Serving | Protein |
|---|---|---|
| Chicken breast, cooked | 100 g | 31 g |
| Lean beef, cooked | 100 g | 26 g |
| Salmon, cooked | 100 g | 25 g |
| Eggs | 2 large | 12.5 g |
| Greek yogurt, plain | 170 g (¾ cup) | 17 g |
| Cottage cheese | 1 cup | 25 g |
| Lentils, cooked | 1 cup | 18 g |
| Tofu, firm | 100 g | 17 g |
| Whey protein powder | 1 scoop (30 g) | 24 g |
| Milk | 1 cup | 8 g |
| Peanut butter | 2 tbsp | 7 g |
Protein and calories
Protein has 4 kcal per gram, so a 135 g target is 540 kcal — about 25% of a 2,200 kcal day. High-protein diets (25–35% of calories) are more filling per calorie and cost slightly more energy to digest, which is part of why they help with fat loss. The calculator reports your target as a share of estimated maintenance calories so it can be reconciled with a macro plan.
Special cases and cautions
Older adults need more protein per kilogram — 1.0–1.2 g/kg and more when ill or recovering — because muscle becomes less responsive to it with age. Pregnancy raises the requirement to about 1.1 g/kg. People with kidney disease are usually advised to limit protein and should follow their clinician's target rather than any general figure. For everyone else, intakes up to about 2 g/kg have not been shown to harm kidneys or bones in long-term studies of healthy adults.
- RDA: 0.8 g/kg — a minimum, not a target for active people.
- Active adults: 1.2–1.6 g/kg; strength training: 1.6–2.2; dieting athletes: 1.8–2.4.
- Over 65: 1.0–1.2 g/kg or more.
- Spread across 3–5 meals of 25–40 g each.
- Kidney disease: follow medical advice.