Protein Intake Calculator

Protein needs aren't the same for everyone — how much your body actually needs depends heavily on body weight and how physically active you are. This calculator estimates a daily protein target by combining your weight with your activity level, scaling up from the standard baseline as activity increases.

The sedentary figure — 0.8 grams of protein per kilogram of body weight — is the RDA (Recommended Dietary Allowance) set by the U.S./Canada Dietary Reference Intakes. It's a precisely established number designed to meet the needs of nearly all healthy, largely inactive adults, and it's the most solidly backed figure this calculator uses.

For anyone more active, protein needs rise — exercise, especially strength training, creates muscle damage that the body repairs using protein. Sports nutrition research generally supports higher intakes for active individuals, commonly citing a range of roughly 1.2 to 2.0 grams per kilogram depending on training intensity and goals. Unlike the RDA, there's no single universally agreed number within that range — this calculator uses a practical, gradually increasing scale across activity levels rather than one precisely cited figure per tier, and the FAQ below explains that distinction in more detail.

A worked example

Say you weigh 80 kg and select "moderately active." This calculator's table sets 1.4 g of protein per kg of body weight at that tier, so 80 × 1.4 = 112 g of protein per day — the exact calculation the result panel runs on your own weight and activity selection. Change only the activity level to "sedentary" (0.8 g/kg) with the same 80 kg body weight, and the target drops to 80 × 0.8 = 64 g/day — the same body, a very different number, entirely because of activity level.

A common misconception

More protein isn't automatically better once you're already above your target — protein needs have a practical ceiling tied to activity level and goals, not an "always higher is better" curve. It's also easy to conflate two different global figures: the U.S./Canada Dietary Reference Intakes set the RDA at 0.8 g/kg, while a 2007 joint WHO/FAO/UNU expert report (WHO Technical Report Series 935) set a very similar "safe intake" of 0.83 g/kg for the same sedentary baseline — two independent expert bodies landing within 0.03 g/kg of each other. That closeness is a sign the sedentary figure is genuinely well-established, not that one of the two numbers is wrong.

Special cases the standard range doesn't fully cover

The 1.2–2.0 g/kg activity-tiered range on this calculator reflects general training; it doesn't account for active weight loss. The International Society of Sports Nutrition's position stand notes that during a calorie deficit, resistance-trained individuals may need substantially more — 2.3 to 3.1 g/kg — to help protect muscle mass while losing fat, meaningfully above what this calculator's "active" or "very active" tiers estimate. The same position stand also found that spreading protein across the day in doses of roughly 20–25 g every few hours supports muscle protein synthesis better than concentrating the same daily total into one or two large meals — so how your total is distributed across meals matters, not just the total itself.

How to use your target

Treat the number as a daily total to build meals toward, not a threshold to hit exactly every single day — a day or two below target rarely matters if your weekly average lands near it. If you're actively trying to lose weight while preserving muscle, or you're a resistance-trained athlete in a calorie deficit, the special case above is worth discussing with a coach or dietitian, since this calculator's tiers are built for general activity levels, not deficit-specific needs.

Comparing the sources behind this number

The sedentary baseline (0.8 g/kg) is the most rigorously established figure here, set by the Institute of Medicine's Dietary Reference Intakes and independently corroborated by the WHO/FAO/UNU's 0.83 g/kg safe intake level. The higher, activity-scaled tiers (1.2–2.0 g/kg) rest on a different kind of evidence — sports nutrition research showing protein needs rise with training load, without one single number the field agrees is exactly correct. Both are legitimate, sourced figures; they just carry different degrees of precision, which is why this calculator presents the sedentary number as a firm RDA and the higher tiers as a practical range.