Protein Intake Calculator
The recommended daily allowance of 0.8g per kilogram is a floor for avoiding deficiency, not a target for anyone training. Reading it as a target is the most common mistake in this area.
Protein
152g a day
- Range
- 128 to 176 g
- Per kilogram
- 1.6 to 2.2 g
- Calories from protein
- 608
- Across four meals
- 38 g each
- The recommended daily allowance of 0.8g per kilogram is a floor for avoiding deficiency, not a target for anyone training. Reading it as a target is the most common mistake in this whole area.
- Spreading it across the day works better than one large serving, because the body can only use so much at once for tissue repair. Four meals of similar size is a reasonable default.
- If you are carrying a lot of fat, work from lean mass or a target weight rather than current weight — protein needs scale with the tissue that uses it.
About protein intake
The RDA exists to answer a narrow question: how little protein can most people eat without developing a deficiency. That is a useful public health floor and it is not advice about performance, body composition or ageing. Someone training gets more from roughly twice it.
The ranges here are the ones the research supports for different purposes. Sedentary sits near the RDA at 0.8 to 1.0 grams per kilogram. General activity is 1.2 to 1.6. Building muscle is 1.6 to 2.2, and there is little evidence of benefit past the top of that. Losing weight sits highest of all at 2.0 to 2.6, because protein is what preserves muscle when calories are short.
Spreading it across the day works better than one large serving. The body can only use so much at once for tissue repair, and roughly 0.4 grams per kilogram per meal across four meals is a reasonable structure — around 38 grams each for an 80kg person aiming at the middle of the muscle-building range.
If you are carrying a lot of fat, work from lean mass or a target weight rather than current weight. Protein needs scale with the tissue that uses it, and fat mass does not use much.
The other thing worth saying: protein is the most filling of the three macronutrients by a clear margin. For anyone in a deficit that is at least as useful as anything it does for muscle.
What it works out
- A daily range in grams for your weight and goal
- Grams per kilogram, to compare against guidance
- How much per meal across four meals
The formula
Grams per day = Weight in kg × grams per kilogram for your goal
Multiplication, and the whole question is which multiplier.
At 80kg building muscle, the range of 1.6 to 2.2 grams per kilogram is 128 to 176 grams a day. The midpoint is 152, which is 608 calories of protein, or about 38 grams at each of four meals.
The ranges are: 0.8 to 1.0 sedentary, 1.2 to 1.6 generally active, 1.6 to 2.2 building muscle, 2.0 to 2.6 losing fat. The last being the highest surprises people — the logic is that when calories are short the body will take amino acids from muscle unless there are enough coming in from food.
There is little evidence of further benefit past about 2.2 grams per kilogram for muscle building. Higher intakes are not harmful in healthy people with normal kidney function, they simply stop doing more.
Working from lean mass rather than total weight is more accurate for anyone carrying substantial fat, because it is muscle that uses the protein.
- Weight
- Body weight, or lean mass if you know it and are carrying a lot of fat.
- Grams per kilo
- Set by what you are training for. 0.8 is a deficiency floor, not a target.
A worked example
An 80 kilogram person training to build muscle.
That works out to 152 g a day.
- Range
- 128 to 176 g
- Per kilogram
- 1.6 to 2.2 g
- Calories from protein
- 608
- Across four meals
- 38 g each
Questions
How much protein do I need a day?
For an 80kg person building muscle, 128 to 176 grams. Generally active is lower at 96 to 128, and the RDA floor is only 64 — which is a deficiency threshold rather than a target.
Is 0.8g per kg enough?
It is enough to avoid deficiency, which is what it was set to do. It is not enough to support training, and there is reasonable evidence that older adults do better above it too.
Can I eat too much protein?
In healthy people with normal kidney function, high intakes have not been shown to cause harm. Past about 2.2 grams per kilogram they simply stop adding benefit, and the calories could be doing something else.
Does it matter when I eat it?
Spreading it helps. The body can only use so much at once for tissue repair, so four moderate servings beats one large one. The "anabolic window" straight after training is far less critical than was once thought.
Why is protein higher when losing weight?
Because in a deficit the body will break down muscle for amino acids unless enough is coming in. Higher protein is what keeps the weight you lose predominantly fat, and it is also the most filling of the three macronutrients.
Should I use body weight or lean mass?
Lean mass, if you know it and are carrying substantial fat — protein needs scale with the tissue that uses it. For most people at a normal body composition the difference is small enough not to matter.
Do I need protein powder?
No. It is a convenient way to hit a target and nothing more — it has no advantage over food of the same protein content. It is useful precisely when getting there from meals is inconvenient.