Protein Calculator

Protein is the one macro that decides whether the weight you lose is fat or muscle — and whether the weight you gain is muscle or fat. This calculator turns the research ranges into one clear daily target for your body weight and your goal.

How the Protein Calculator Works

Your target is based on grams of protein per kilogram of body weight, matched to your goal:

• Lose fat (deficit): 2.2 g/kg — a deficit puts muscle at risk, so protein goes up
• Build muscle: 2.0 g/kg — the top of the range shown to maximise muscle growth
• Endurance athlete: 1.6 g/kg — long training days increase protein turnover
• Maintain / general health: 1.4 g/kg — comfortably above the minimum for active people

For comparison, the bare minimum RDA for a sedentary adult is only 0.8 g/kg — enough to avoid deficiency, not enough to support training or dieting well.

Worked Example

An 80 kg person building muscle: 80 × 2.0 = 160 g of protein per day (640 kcal). Split across four meals, that is about 40 g per meal — a palm-and-a-half of chicken, fish, eggs or Greek yogurt per sitting.

Good Protein Sources

• Animal: chicken, fish, eggs, Greek yogurt, cottage cheese, milk, lean beef
• Plant: lentils, chickpeas, tofu, tempeh, edamame — combine sources across the day
• Convenient: whey or plant protein powder — fine as a top-up, not a food replacement

Once you have your protein target, use the Macro Calculator to split the rest of your calories between carbs and fat.

Frequently Asked Questions

How much protein do I need to build muscle?
Around 1.6–2.2 g per kg of body weight per day covers almost everyone. This calculator uses 2.0 g/kg for muscle gain — near the top of the evidence-based range, with no benefit shown above about 2.2 g/kg.

Is too much protein bad for my kidneys?
In healthy adults, studies of up to roughly 3 g/kg have not shown kidney harm. People with existing kidney disease should follow their doctor’s advice instead of any calculator.

Does protein timing matter?
Far less than your daily total. Spreading protein across 3–5 meals helps slightly; hitting the daily number matters most.

Can I build muscle on plant protein only?
Yes — total amount matters most. Plant eaters should lean toward the top of the range and vary sources (beans, lentils, soy, grains) to cover all essential amino acids.