Protein Calculator
If you only nail one macro, make it this one. Protein has the biggest impact on body composition and satiety.
How your protein target is calculated
Protein targets scale linearly with body weight and depend on your training and dieting context. The calculator multiplies your weight (kg) by a goal-specific factor drawn from ISSN, ACSM, and recent meta-analyses.
Daily protein (g) = body weight (lb) × goal multiplier × 0.4536
The multipliers (g/kg/day)
- 0.8 — Sedentary maintenance: RDA floor.
- 1.4 — Active / general fitness: supports recovery for 3–5 workouts/week.
- 1.8 — Muscle gain: hypertrophy sweet spot (Morton 2018 meta-analysis).
- 2.0 — Fat loss: preserves muscle in a deficit (Helms 2014).
- 2.2 — Competitive athlete: upper end of the ISSN range.
If you carry significant excess body fat, plug in your goal weight instead of total weight. More detail in our protein requirements guide.
Worked example
A 70 kg lifter aiming to build muscle: 70 × 1.8 = 126 g/day. Across 4 meals, that's ~32 g per meal — roughly one large chicken breast, six eggs, or a 200 g salmon fillet.
Why calculating your protein intake matters
- It protects muscle during fat loss. In a calorie deficit, low protein turns "weight loss" into muscle loss. High protein keeps the loss almost entirely fat.
- It controls hunger. Protein is the most satiating macro — about 25% of its calories are burned in digestion, and it suppresses ghrelin more than carbs or fat.
- It builds visible muscle. Lifting without enough protein is like construction without enough bricks. Hitting your target turns workouts into actual physique change.
- It's the easiest macro to under-eat. Most people running on the standard Western diet land around 0.6–0.9 g/kg — well below what's optimal. Tracking it for a week is usually a wake-up call.
- It compounds over years. Adequate protein is one of the strongest predictors of muscle retention as you age — and muscle is the strongest predictor of healthy aging.
High-protein foods (per 100 g)
- Chicken breast (cooked) — 31 g
- Greek yogurt (0% fat) — 10 g
- Salmon — 25 g
- Whey isolate (1 scoop) — 25 g
- Lentils (cooked) — 9 g
- Eggs (1 large) — 6 g
- Tofu (firm) — 17 g
- Cottage cheese — 11 g
FAQ
How much protein do I need per day?
The RDA of 0.8 g/kg is a deficiency minimum, not an optimum. Active adults thrive on 1.2–1.6 g/kg. Fat loss or muscle gain benefit from 1.6–2.2 g/kg. Above ~2.2 g/kg, additional protein offers no demonstrated benefit.
Is too much protein bad for your kidneys?
In people with healthy kidneys, intakes up to 2.5–3 g/kg show no adverse renal effects in controlled studies. The 'high protein damages kidneys' claim comes from people with pre-existing kidney disease.
How much protein per meal?
Muscle protein synthesis maxes out around 0.4 g/kg per meal (~30–40 g for most people). Spreading protein across 3–5 meals optimizes 24-hour muscle protein balance.
Do I need protein after a workout?
The 'anabolic window' is wider than gym lore suggests — anywhere from 1 hour before to 4–6 hours after training works. Total daily intake matters more than timing.
Plant vs animal protein?
Animal proteins have higher leucine and a more complete amino-acid profile. Plant eaters can match results by eating ~15–20% more total protein and combining sources.
Sources
- Jäger R, et al. ISSN Position Stand: protein and exercise. JISSN. 2017;14:20.
- Helms ER, et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. IJSNEM. 2014;24(2):127–38.
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training–induced gains. Br J Sports Med. 2018;52:376–84.