Daily Protein Intake Calculator
Calculates how many grams of protein to eat per day based on your body weight and how active you are. It scales recognised grams-per-kilogram guidelines so you get a target suited to sedentary living, general fitness, or serious strength and endurance training.
Last updated: May 2026
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About this calculator
Protein needs scale with body weight and activity, which is why nutrition science expresses targets in grams per kilogram of body weight (g/kg) rather than as a single number. The Recommended Dietary Allowance (RDA) of 0.8 g/kg is a floor designed to prevent deficiency in sedentary adults — not an optimal intake for active people. Research on athletes and resistance trainers consistently supports higher intakes: roughly 1.2–1.6 g/kg for general fitness and muscle maintenance, 1.6–2.0 g/kg to build muscle, and up to about 2.2 g/kg during a calorie deficit, where higher protein protects lean mass and increases satiety. This calculator multiplies your weight by the g/kg figure tied to your selected activity level. For a 70 kg person training regularly at 1.6 g/kg, that is 112 g of protein per day. Spreading intake across three or four meals of 25–40 g each maximises muscle-protein synthesis better than loading it all at dinner. Protein quality matters too: animal sources and soy are "complete", while most plant sources need to be combined across the day to cover all essential amino acids. Very high intakes (above ~2.2 g/kg) show diminishing returns for muscle and simply add calories. People with chronic kidney disease are an important exception and should follow medically supervised, often lower, protein targets. Use total body weight for lean individuals; very overweight people may prefer to calculate from a target or lean body weight to avoid overshooting.
How to use
Example 1 — Gym-goer building muscle. A 70 kg person who lifts several times a week selects "Regular exercise / muscle gain — 1.6 g/kg" and enters 70. Result: 112 g/day. Verify: 70 × 1.6 = 112. ✓ Split across four meals, that is about 28 g per meal. Example 2 — Sedentary adult. A 60 kg person with a desk job and little exercise selects "Sedentary (RDA minimum) — 0.8 g/kg" and enters 60. Result: 48 g/day. Verify: 60 × 0.8 = 48. ✓ This meets the RDA floor; bumping activity up to 1.2 g/kg would raise the target to 72 g.
Frequently asked questions
How much protein do I really need per day?
It depends on your weight and activity. The RDA of 0.8 g/kg prevents deficiency in sedentary adults, but most fitness and sports-nutrition bodies recommend more: about 1.2–1.6 g/kg for active people and muscle maintenance, 1.6–2.0 g/kg to build muscle with resistance training, and up to 2.2 g/kg when dieting to preserve lean mass. So a 70 kg active adult typically needs 112–140 g, not the 56 g the RDA would suggest. Going much above 2.2 g/kg rarely adds benefit and just contributes extra calories. Pick the activity level that matches your real training, not your aspirations.
Should I use total body weight or lean body weight?
For people at a healthy weight, total body weight works fine and is what most guidelines assume. If you carry significant excess fat, using total weight can overstate your needs because fat tissue does not require much protein to maintain — in that case, calculating from lean body mass or a realistic target weight gives a more sensible figure. For example, a very overweight person might use their goal weight rather than current weight. When in doubt, lean toward the higher end of a moderate range; it is hard to eat too much protein within normal diets, and the main downside is extra calories.
Does it matter when and how I spread protein across the day?
Yes. Muscle-protein synthesis responds best to doses of roughly 25–40 g of high-quality protein spread across three or four meals, rather than one large serving. Eating 100 g all at dinner is less effective for building muscle than splitting it into four 25 g meals. Including protein at breakfast is especially helpful because many people skew their intake toward the evening. Around training, having protein within a few hours before or after a workout supports recovery, though total daily intake matters far more than precise timing for most people.
What are common mistakes when setting a protein target?
A frequent error is confusing grams of protein with grams of a protein-containing food — 100 g of chicken breast contains only about 31 g of protein, not 100 g. Another is choosing an activity level that reflects ambition rather than actual training, which inflates the target. People also forget that plant-based eaters need slightly more total protein and more variety to cover all essential amino acids. Finally, chasing extremely high intakes (3+ g/kg) wastes money and calories with no added muscle benefit. Track actual grams using labels or an app for a few days to calibrate.
When should I not use this calculator?
Do not use these targets if you have chronic kidney disease or reduced kidney function — high protein can accelerate decline, and you should follow a renal dietitian’s individualised (often lower) prescription. People with certain liver conditions, those on dialysis, and individuals with rare metabolic disorders also need medical guidance rather than general g/kg rules. Pregnant and breastfeeding women have specific increased needs best set with a clinician. For everyone else who is healthy, these ranges are a safe and well-supported starting point, but adjust based on how your body, training, and recovery respond.