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Protein Calculator

Find how much protein you should eat per day to build muscle, lose fat or maintain — based on your bodyweight and goal, in grams you can actually plan around.

Units
Goal
Daily protein135180g/day

A practical target is around 158 g/day — roughly 40 g across 4 meals.

Per kg bodyweight1.82.4g
Per lb bodyweight0.81.1g
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Estimates for general guidance, not medical advice. Formulas carry a 5–10% margin — use them as a starting point and adjust from real results.

How much protein you need

Protein needs scale with your bodyweight and what you're trying to do, not with a single one-size number. The old 'RDA' of 0.8g per kg only prevents deficiency — it's far too low for anyone training or dieting. For body composition, the research consistently lands in the 1.6–2.2g per kg of bodyweight range (roughly 0.7–1.0g per lb).

This calculator places you within that evidence-based band based on your goal: higher when you're losing fat (extra protein protects muscle in a calorie deficit and keeps you full), and solidly in range when you're building muscle or maintaining. It returns a low–high range plus a practical mid-point you can aim for daily.

Why protein is the macro that matters most

If you only get one macro right, make it protein. It does three things no other macro does as well: it builds and preserves muscle, it's the most filling per calorie (which makes fat loss far easier), and it has the highest thermic effect — your body burns ~20–30% of protein calories just digesting it, versus a few percent for carbs and fat. That's why high-protein diets make staying in a deficit feel less like a fight. More on the science in protein myths debunked.

Spreading protein across your day

Total daily protein is what matters most, but distribution helps. Aim for roughly 0.4g per kg per meal across 3–4 meals to maximise muscle-building stimulus throughout the day, rather than packing it all into dinner. The calculator shows a per-meal figure so you have a concrete target for each plate.

Hitting 150g+ of protein a day is harder than it sounds until you start measuring it — most people overestimate how much they eat. Macroo shows your protein adding up in real time as you log meals in plain English, so you know by mid-afternoon whether you need a higher-protein dinner. One-time $9.99, no subscription.

Common questions

Protein Calculator FAQ

  1. 01

    How much protein do I need to build muscle?

    About 1.6–2.2g per kg of bodyweight per day (roughly 0.7–1.0g per lb), paired with resistance training and enough total calories. Going much above ~2.2g/kg doesn't build extra muscle — it just adds calories. Enter your weight above for your exact range.

  2. 02

    Can you eat too much protein?

    For healthy people, high-protein diets are safe and well-studied. The main downside of eating far beyond your needs is opportunity cost — those calories could come from carbs or fat that fuel training or balance your meals. There's no muscle-building benefit beyond roughly 2.2g/kg.

  3. 03

    How much protein per meal?

    Around 0.4g per kg of bodyweight per meal, across 3–4 meals, is a good target for muscle protein synthesis. For an 80 kg person that's roughly 30g per meal. The calculator shows your per-meal number based on your weight.

  4. 04

    Do I need more protein when losing weight?

    Yes. In a calorie deficit, higher protein protects the muscle you'd otherwise lose and keeps hunger in check, which is why this calculator pushes the range higher for fat loss. Aim toward the top of your range when cutting.

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