Protein is the building block your body uses to repair muscle, make hormones, and keep you full between meals. Yet most people guess at how much they actually need — and the right number changes dramatically depending on whether you sit at a desk, run marathons, or lift weights. This protein intake calculator turns your body weight and goal into a concrete daily target in grams, then splits it into per-meal portions so you know exactly what to put on your plate.
Adjust your weight, unit, goal, and meals per day, and every figure updates instantly. A 180-pound lifter, for example, lands near 131 grams per day — or roughly 33 grams across four meals.
How to Use
- Enter your Body Weight. This is the single most important input; protein targets scale directly with how much you weigh.
- Pick your Weight Unit — pounds (US) or kilograms (metric). The calculator converts internally, so you never have to do the math.
- Choose your Goal / Activity. Sedentary adults need the basic RDA, while lifters and people cutting fat need substantially more. This setting picks the grams-per-kilogram multiplier for you.
- Set your Meals per Day. Most people spread protein over 3–5 feedings; the calculator divides your daily target evenly so you hit the same number at breakfast, lunch, dinner, and snacks.
The result card shows your converted weight in kilograms, your Protein per Day target (highlighted), the Grams per Meal that targets works out to, and the quick 1 g/lb Rule of Thumb for a gut-check number.
The Formula Behind the Number
Protein targets are expressed in grams per kilogram of body weight, which is why the calculator first converts your weight to kilograms (1 lb = 0.453592 kg):
Protein per Day = Weight (kg) × Multiplier (g/kg)
The multiplier comes from the International Society of Sports Nutrition position stand on protein and exercise:
- Sedentary — 0.8 g/kg, the basic RDA to avoid deficiency.
- Active — 1.2 g/kg, for regular recreational exercise.
- Endurance — 1.6 g/kg, for runners and cyclists doing long sessions.
- Strength / lifter — 1.6 g/kg, the evidence-based sweet spot for muscle growth and retention.
- Cutting — 2.2 g/kg, used during aggressive dieting to protect muscle while losing fat.
Worked example: a 180 lb lifter weighs 81.65 kg. At 1.6 g/kg that is 81.65 × 1.6 = 130.63 g per day. Split across 4 meals, that is about 32.66 g per meal. The old "1 gram per pound" rule — 180 g in this case — is a convenient but slightly generous shortcut, which is why the calculator shows it separately rather than as your primary target.
Why Per-Meal Timing Matters
Hitting 130 g in one sitting is not the same as hitting it across the day. Research suggests muscle protein synthesis responds best when you spread protein into 3–4 servings of roughly 25–40 g each. That is roughly the protein in a scoop of whey, two eggs plus Greek yogurt, a palm-sized chicken breast, or a cup of cottage cheese. Your meal count input exists so the target lands in a realistic, absorbable shape.
As a frame of reference, protein should make up about 10–35% of your total daily calories on a typical diet; an active lifter leaning toward the upper end. If you are buying protein powder to fill gaps, a 2 lb tub usually runs $25–$45 and delivers 25–30 servings — a cheap way to top off a shortfall rather than a meal replacement.
Examples
Example 1 — A 180 lb lifter. At 180 lb, strength goal, 4 meals: the calculator converts to 81.65 kg and returns 130.63 g per day, or 32.66 g per meal. The 1 g/lb shortcut suggests 180 g, which is about 38 g higher — fine for a bulking phase, but the primary 1.6 g/kg target is the number to plan around.
Example 2 — A 70 kg dieter cutting fat. Enter 70 kg, cutting goal, 3 meals. The target jumps to 70 × 2.2 = 154.0 g per day, split into 51.33 g per meal. The higher multiplier protects lean muscle during a calorie deficit, when the body is more likely to burn it for fuel.
Example 3 — A 150 lb active office worker. At 150 lb, active goal, 3 meals: 68.04 kg × 1.2 = 81.65 g per day, or 27.22 g per meal. This is a realistic, easy-to-hit number — one protein shake plus normal meals gets most people there.
FAQ
How much protein do I actually need per day?
For most people it is 0.8–2.2 g per kilogram of body weight. Sedentary adults need about 0.8 g/kg, regular exercisers 1.2–1.6 g/kg, and lifters or people cutting fat 1.6–2.2 g/kg. Enter your weight and goal above for a precise daily number.
Is 1 gram of protein per pound enough?
The "1 g per pound" rule is a simple shortcut, not a precise target. For a 180 lb lifter it suggests 180 g, while the evidence-based 1.6 g/kg target is about 131 g. The 1 g/lb rule works as a generous upper bound for bulking, but it overshoots for sedentary people and is not necessary for most lifters.
How much protein per meal do I need?
Aim for 25–40 g of protein per meal, spread across 3–4 meals a day. This range best stimulates muscle protein synthesis. The calculator divides your daily target by your meal count so each sitting lands in that range automatically.
Can you eat too much protein?
For healthy adults, very high protein intakes are generally safe. The main practical limit is cost and food volume — eating 2.2 g/kg during a cut is fine, but pushing well above that offers no extra muscle-building benefit and simply displaces other nutrients from your diet.
Should I use protein powder to hit my target?
Protein powder is a convenient way to fill gaps, not a required meal. One scoop (25–30 g) per day closes a shortfall cheaply (a tub runs roughly $25–$45), but whole foods like chicken, fish, eggs, Greek yogurt, and beans should form the foundation.
Does protein help with weight loss?
Yes. Higher protein keeps you fuller, preserves muscle while you cut calories, and costs more energy to digest. During a calorie deficit, bumping toward 2.2 g/kg helps ensure the weight you lose is fat, not muscle.
Disclaimer
This protein intake calculator is provided for informational purposes only and is not medical advice. Targets are estimates based on published sports-nutrition guidelines and your entered inputs; individual needs vary with health status, kidney function, pregnancy, and specific medical conditions. Consult a doctor or registered dietitian before making major changes to your diet, especially if you have kidney disease, diabetes, or are pregnant or breastfeeding.