Protein Intake Calculator
This protein calculator gives your daily protein intake in grams, matched to your body weight and goal — from general health up to muscle building and cutting.
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Formula: Mifflin-St Jeor (1990). General fitness information, not medical advice.
How much protein you really need
The classic 0.8 g per kilogram of body weight is the U.S. RDA — the minimum to avoid deficiency in sedentary adults, not the amount that supports training. Research on athletes, including the International Society of Sports Nutrition position stand, consistently lands between 1.4 and 2.0 g/kg: the harder you train and the leaner you're trying to get, the higher you go, with the top of the range most useful in a calorie deficit where protein protects muscle. Spreading your total across 3–5 meals of 25–40 g each makes it easier to hit and better for muscle protein synthesis. These are general guidelines, not medical advice — anyone with kidney disease should talk to a doctor before raising protein substantially.
Worked example. Take a 180 lb lifter who wants to build muscle. Convert weight to kilograms first: 180 ÷ 2.205 = 81.6 kg. Multiply by the muscle-building factor of 1.8 g/kg: 81.6 × 1.8 ≈ 147 g of protein per day. Split across four meals, that's about 37 g each — say a chicken breast, a cup of Greek yogurt, a three-egg omelette and a scoop of whey.
Daily protein by body weight and goal (grams/day)
| Body weight | Sedentary 0.8 | Active 1.4 | Muscle 1.8 | Cutting 2.0 |
|---|---|---|---|---|
| 130 lb (59 kg) | 47 g | 83 g | 106 g | 118 g |
| 150 lb (68 kg) | 54 g | 95 g | 122 g | 136 g |
| 170 lb (77 kg) | 62 g | 108 g | 139 g | 154 g |
| 190 lb (86 kg) | 69 g | 121 g | 155 g | 172 g |
| 210 lb (95 kg) | 76 g | 133 g | 171 g | 191 g |
Figures are body weight in kg × the goal factor, rounded. Guidance follows the ISSN and ACSM protein recommendations for active adults; general fitness information, not medical advice.