Key takeaways
- The RDA of 0.8 g/kg prevents deficiency. It is not the number that supports body composition.
- For general health, aim for 1.2–1.6 g/kg of body weight per day.
- In a calorie deficit or a muscle-building phase, 1.6–2.2 g/kg is the better-supported range.
- Split it into 25–40 g doses across 3–4 meals rather than loading it all at dinner.
Protein is the most searched macronutrient of the year, and also the most misunderstood. Most people asking “how much protein per day?” get a number back with no units attached to their own body — so here is the calculation, the range for each goal, and what it looks like on an actual plate.
The short answer, in grams
Protein needs scale with body weight, so the useful unit is grams per kilogram of body weight per day (g/kg). Take your weight in kilograms — pounds divided by 2.2 — and multiply by the figure for your goal.
| Goal | Target (g/kg/day) | 70 kg / 154 lb person | 90 kg / 198 lb person |
|---|---|---|---|
| Avoiding deficiency (RDA) | 0.8 | 56 g | 72 g |
| General health, active adult | 1.2 – 1.6 | 84 – 112 g | 108 – 144 g |
| Fat loss (preserving muscle) | 1.6 – 2.2 | 112 – 154 g | 144 – 198 g |
| Building muscle | 1.6 – 2.2 | 112 – 154 g | 144 – 198 g |
| Older adults (60+) | 1.2 – 1.6 | 84 – 112 g | 108 – 144 g |
If you carry a lot of excess body fat, calculating from goal weight or lean body mass rather than current weight avoids an unrealistically high target.
Why the RDA is so much lower
The Recommended Dietary Allowance of 0.8 g/kg answers a narrow question: what is the minimum needed to stop nitrogen balance going negative in most healthy adults? That is a deficiency threshold, not an optimum. Updated dietary guidance has moved the healthy range up to roughly 1.2–1.6 g/kg, which is far closer to what the exercise and body-composition literature has recommended for years.
Why protein does more than build muscle
Three distinct mechanisms make protein the macronutrient worth getting right first, before you optimise anything else.
20–30%
Thermic effect
The share of protein's calories burned during digestion — against 5–10% for carbs and 0–3% for fat.
#1
Most satiating macro
Gram for gram, protein reduces subsequent intake more than carbohydrate or fat.
Muscle
Retained in a deficit
Adequate protein shifts the composition of weight lost toward fat rather than lean mass.
That last point is the one most people miss. In a calorie deficit your body needs amino acids from somewhere, and if you do not eat enough it will take them from muscle tissue. Two people can lose the same 8 kg on the scale, and end up in very different places depending on how much of it was lean mass — and since muscle is metabolically active, losing it lowers the TDEE you have to work with afterwards.
How to split it across the day
Total daily intake matters most, but distribution makes a large target achievable. Muscle protein synthesis responds strongly to doses in the 25–40 g range, and hitting 150 g is far easier across four meals of 35 g than as one enormous dinner.
- 1Anchor breakfast. This is where most people lose 20–30 g. Eggs, Greek yogurt, cottage cheese, or a shake all clear 25 g without much effort.
- 2Build lunch and dinner around the protein. Pick the protein first, then add carbohydrate and vegetables around it, rather than the other way round.
- 3Make one snack count. A single protein-forward snack — yogurt, jerky, edamame, a shake — closes a 20–30 g gap that would otherwise carry over.
- 4Check the weekly average, not the daily one. A day at 110 g when you were aiming for 140 g is not a problem. Five of them in a row is.
What 30 g of protein actually looks like
| Food | Portion | Protein | Calories (approx.) |
|---|---|---|---|
| Chicken breast, cooked | 110 g / 4 oz | 33 g | 185 |
| Greek yogurt, 0% fat | 200 g / 7 oz | 20 g | 120 |
| Cottage cheese, 2% | 150 g / 5 oz | 17 g | 120 |
| Eggs | 3 large | 19 g | 215 |
| Whey protein | 1 scoop (30 g) | 24 g | 120 |
| Salmon, cooked | 110 g / 4 oz | 28 g | 230 |
| Lentils, cooked | 200 g / 1 cup | 18 g | 230 |
| Firm tofu | 150 g / 5 oz | 17 g | 170 |
Values vary by brand and preparation — check the label or scan the barcode for the exact figures.
Hitting a protein target is a counting problem
2BIB tracks protein against your daily target as you log. Snap a photo of the plate and the AI returns a per-item macro breakdown, so you can see the gap before dinner instead of after.
Common mistakes
Using a round number instead of your weight
Counting the whole food, not the protein
Back-loading everything to dinner
Ignoring protein quality
Cutting fat and carbs to make room
Assuming more is always better
Protein by goal
If you are losing weight
Go to the upper end: 1.6–2.2 g/kg. The deficit is exactly when muscle is at risk, and protein is also your best defence against hunger. Pair it with resistance training two to three times a week — the training signals your body to keep the muscle, the protein supplies the material. See the full fat loss guide.
If you are building muscle
The same 1.6–2.2 g/kg range applies, but now inside a modest calorie surplus of roughly 250–500 kcal per day. Research on higher intakes shows diminishing returns above about 2.2 g/kg for most trainees. See the muscle-building guide.
If you are maintaining
1.2–1.6 g/kg keeps body composition stable and supports recovery without dominating your plate. See the maintenance guide.
If you are over 60
Older adults experience anabolic resistance — the same dose of protein triggers a weaker muscle-building response. Staying at the top of the 1.2–1.6 g/kg range, with at least 25–30 g per meal, helps offset it.
When to ask a professional first
If you have chronic kidney disease, liver disease, or are pregnant, protein recommendations change and should come from your doctor or a registered dietitian. Everything here is general education, not medical advice.
A simple way to start
- Weigh yourself, convert to kilograms, and multiply by 1.6 — that is your working target for most goals.
- Divide by four. That is your per-meal number, and it is the only figure you need to remember day to day.
- Track for two weeks without changing anything else. Most people discover they are 30–50 g short of where they assumed they were.
- Adjust one meal at a time. Breakfast first — it is almost always the weakest.
Once your protein target is consistently met, the rest of the plan gets easier: hunger drops, training recovery improves, and the calorie target you set from your TDEE becomes something you can actually hold onto. Run your split through the free macro calculator to see how protein, carbs, and fat divide up at your calorie level.