Protein Calculator
Your daily protein target in grams, from RDA baseline to training and cutting ranges.
Formula: Mifflin-St Jeor (Katch-McArdle when body fat % is given) × activity factor. Every constant is documented on the methodology page. Educational estimate — not medical advice.
Daily protein by body weight
Grams per day. Ranges: RDA baseline 0.8–1.2 g/kg · training 1.4–2.0 g/kg (ISSN) · fat loss 1.8–2.4 g/kg · muscle gain 1.6–2.2 g/kg.
| Body weight | General health | Regular training | Fat loss | Muscle gain |
|---|---|---|---|---|
| 120 lb | 44–65 g | 76–109 g | 98–131 g | 87–120 g |
| 140 lb | 51–76 g | 89–127 g | 114–152 g | 102–140 g |
| 160 lb | 58–87 g | 102–145 g | 131–174 g | 116–160 g |
| 180 lb | 65–98 g | 114–163 g | 147–196 g | 131–180 g |
| 200 lb | 73–109 g | 127–181 g | 163–218 g | 145–200 g |
| 220 lb | 80–120 g | 140–200 g | 180–239 g | 160–220 g |
| 240 lb | 87–131 g | 152–218 g | 196–261 g | 174–239 g |
| 260 lb | 94–142 g | 165–236 g | 212–283 g | 189–259 g |
How much protein do you actually need?
The official RDA of 0.8 g per kilogram is a floor set to prevent deficiency in sedentary adults, not a target for people who train. The International Society of Sports Nutrition's position stand puts the effective range for building and keeping muscle at 1.4–2.0 g/kg per day, and reviews of dieting athletes support going higher — around 1.8–2.4 g/kg of body weight — when you are in a calorie deficit and trying to hold on to lean mass.
Practical translation: for most people who lift, roughly 0.7–1 g per pound of body weight covers the evidence-backed range. Distribution matters less than the daily total, though 3–5 feedings of 25–40 g each is a sensible default. Whole-food sources first; powder is a convenience, not a requirement.