Protein Calculator
Find how much protein you actually need each day. Enter your bodyweight, how active you are, and your goal, and get a daily range in grams, not a single number pretending to be more precise than the science actually is, plus a per-meal breakdown so you know how to spread it out.
- Daily Protein Range
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- Per Meal (3 meals/day)
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- Per Meal (4 meals/day)
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Assumptions
- Sedentary uses a fixed 0.8 g/kg regardless of which goal you select, because the RDA is calibrated as a baseline for adults with minimal structured activity, not tied to a specific body composition goal. Choose active if you exercise regularly, including resistance training, to see a goal-specific range instead.
- Maintain and build muscle use the same evidence-based range, 1.6 to 2.2 g/kg, because the research doesn't draw a distinct numeric line between the two: what differentiates maintaining muscle from building it is training stimulus and calorie balance, not protein intake itself.
- The lose fat while preserving muscle range, 2.3 to 3.1 g/kg, is higher because protein needs during a calorie deficit are their own specific research question with a dedicated evidence base, separate from the general resistance-training range above.
- Per-meal figures split the midpoint of your daily range evenly across 3 or 4 meals. That's a practical way to apply the daily total, though the underlying daily ranges themselves were partly derived from research using a roughly four-meal-a-day distribution pattern.
- Protein needs vary with kidney function, liver function, and other medical conditions not captured here. This gives general guidance for healthy adults, not medical advice. Talk to a doctor or dietitian before using a high-protein target if you have a relevant condition.
- These ranges describe total daily protein regardless of source. Protein quality and amino acid completeness (animal versus plant sources, for example) can affect how efficiently your body uses it, which this calculator doesn't adjust for.
Sources
- Institute of Medicine (National Academies). Dietary Reference Intakes: Recommended Intakes for Individuals. 0.8 g/kg/day protein RDA for reference body weight.
- Schoenfeld BJ, Aragon AA. "How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution." Journal of the International Society of Sports Nutrition. 2018.
- Jager R, et al. "International Society of Sports Nutrition Position Stand: protein and exercise." Journal of the International Society of Sports Nutrition. 2017.
Why the range is so wide
A gram-per-kilogram target isn't a single physiological constant: it depends on training experience, how hard and how often someone trains, and how precisely researchers can measure something as noisy as long-term muscle protein balance across different people. Rather than pretend to more precision than the evidence supports, the ranges here reflect the actual spread reported in the underlying studies. Treat the low end as a reasonable floor and the high end as a ceiling with little extra benefit above it, not a target to maximize.
Why maintain and build muscle share a number, but fat loss doesn't
It would be easy to assume each goal deserves its own distinct number, but the research doesn't actually support that split evenly. The range commonly cited for building or maintaining muscle in resistance-trained people comes from the same body of evidence and isn't divided further by goal: the meaningful difference between maintaining and building is calorie balance and training progression, not protein intake. Losing fat while preserving muscle is different: dieting in a calorie deficit changes how your body handles protein, and the research specific to that situation supports a genuinely higher range, which is why that option produces a different number here rather than reusing the same one.
Worked example
A 70 kg adult who exercises regularly, including resistance training, aiming to maintain.
70 kg x 1.6 g/kg = 112 g/day at the low end, and 70 kg x 2.2 g/kg = 154 g/day at the high end, giving a range of 112 to 154 g/day. The midpoint, 133 g, splits to about 44 g per meal across 3 meals, or about 33 g per meal across 4 meals.
Frequently asked questions
How much protein intake do I actually need per day?
It depends mainly on how active you are and what you're aiming for. Someone with little structured exercise needs around 0.8 grams per kilogram of bodyweight, the general RDA baseline. Someone who trains regularly, especially with resistance training, generally needs more, commonly 1.6 to 2.2 grams per kilogram, or higher still while dieting and trying to preserve muscle.
How much protein do I need to build muscle?
For someone who trains regularly, the evidence supports 1.6 to 2.2 grams per kilogram of bodyweight per day. That's the same range research supports for simply maintaining muscle, since the two goals aren't separated by a different protein target: what actually drives building versus maintaining is your training stimulus and whether you're in a calorie surplus, not how much protein you eat above that range.
Is protein intake different for women?
The per-kilogram targets here aren't set differently by sex: the research they're based on expresses protein needs relative to bodyweight, and that relationship doesn't have a separately established figure for women versus men. Absolute grams per day will typically come out lower for women mainly because average bodyweight is lower, not because the underlying per-kilogram target itself changes.
Why does this show a daily range instead of one number?
A single number would imply more precision than the research actually supports. Studies on protein needs report ranges because individual training history, workout intensity, and even how a study measured muscle protein balance all shift the result. The range shown reflects that real spread rather than picking one point and hiding the rest.
How much protein should I eat if I'm not exercising much?
Select sedentary and you'll get a fixed 0.8 grams per kilogram of bodyweight, the general RDA baseline for adults with minimal structured activity. That figure doesn't change based on your goal, since without a training stimulus, extra protein alone doesn't reliably build or preserve more muscle than that baseline already covers.
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