Protein Calculator

How much protein you need is one of the most-asked questions in nutrition — and one of the most poorly answered, because the honest answer depends on your weight, your training and your goal. This protein calculator gives you a personal daily target in grams, and the guide below explains where the numbers come from: the official recommended daily protein intake, the higher targets that build muscle, and the point at which more protein stops helping.

Use the calculator for your number, then read on for the evidence behind it — grams per day, grams per pound, protein for weight loss and the common mistakes that quietly sabotage protein targets.

How much protein do I need a day?

The official recommended dietary allowance (RDA) is 0.8 grams of protein per kilogram of body weight per day — about 56 g for an 70 kg (154 lb) adult. But the RDA is a minimum to prevent deficiency in sedentary people, not an optimum. Research consistently supports higher intakes for almost everyone who moves:

The calculator above applies these evidence-based ranges to your own weight and goal instead of handing you a one-size-fits-all number.

How many grams of protein per day — in real food

A gram target only matters if you can picture it on a plate. Rough protein contents of common foods:

• Chicken breast, 100 g cooked — about 31 g protein
• Salmon fillet, 100 g — about 25 g
• 3 large eggs — about 19 g
• Greek yogurt, 200 g — about 20 g
• Lentils, 1 cup cooked — about 18 g
• Firm tofu, 100 g — about 14 g

A 120 g daily target is typically three protein-centred meals plus one snack — demanding but entirely achievable with normal food, with or without meat.

Grams per pound: the simple rule of thumb

If you think in pounds, the conversions are straightforward: the RDA equals about 0.36 g per pound of body weight, active adults do well between 0.55 and 0.75 g per pound, and the muscle-building range is roughly 0.7 to 1 g per pound. The popular gym advice of “one gram per pound of body weight” sits at the very top of the evidence-based range — not harmful for healthy people, but more than most need.

Protein to build muscle

Muscle grows when resistance training is combined with enough protein and enough total calories. The research consensus puts the sweet spot at 1.6–2.2 g/kg per day, with diminishing returns above that. Three practical rules make the target work harder:

• Spread it out. Muscle protein synthesis responds best to 20–40 g doses every 3–4 waking hours, rather than one giant dinner.
• Anchor each meal. Build every meal around a protein source first; carbohydrate and fat follow.
• Pair it with calories. In a calorie deficit, protein protects muscle; for actual gain you also need a modest surplus — our TDEE calculator and macro calculator set those numbers.

Protein for weight loss

During a diet, protein is the macronutrient most worth protecting. Higher-protein diets preserve lean mass while fat is lost, blunt hunger better than carbohydrate or fat, and cost more calories to digest. Practical target: 1.6–2.4 g/kg while in a calorie deficit — towards the higher end if the deficit is aggressive or you train hard. Set the deficit itself with our calorie deficit calculator, then let protein hold the line on muscle.

Can you eat too much protein?

For healthy people, intakes up to about 2 g/kg per day are well studied and considered safe; even higher intakes have not shown harm to healthy kidneys in trials. The important exception: anyone with chronic kidney disease or reduced kidney function should set protein targets with their physician, because damaged kidneys handle protein loads differently. Very high protein also crowds out other foods — fibre, fruit and healthy fats still matter.

What 120 grams looks like in a real day

Targets fail in grams and succeed on plates. A worked day at ~120 g without supplements:

Notice the architecture: every meal anchored by one clear protein source, each landing in the 20–40 g synthesis window — no chugging, no powders required. The most common real-world gap is breakfast: a toast-and-tea morning contributes ~5 g, and the whole day spends itself catching up. Fixing breakfast alone typically adds 20–25 g and is the single highest-leverage habit in protein planning.

Protein quality: complete vs incomplete

Grams are not the whole story — proteins differ in their essential amino acid profiles. Animal sources (meat, fish, eggs, dairy) are “complete”, carrying all nine essential amino acids in strong proportions, with dairy and eggs topping the quality scales. Most single plant sources run short in one amino acid — grains in lysine, legumes in methionine — but the fix is trivially easy: variety across the day completes the profile (rice + lentils, hummus + bread, beans + corn). The amino acid that matters most for muscle is leucine: roughly 2.5–3 g per meal flips on muscle protein synthesis, which a palm-sized meat portion, three eggs, or a generous serving of tofu plus legumes each achieve.

Hitting protein targets without meat

Fully plant-based athletes hit 2 g/kg routinely — it just takes intent:

Practical vegan guidance nudges targets ~10–15% higher to offset lower digestibility — and soy, quinoa and buckwheat are complete proteins on their own.

Protein timing: what actually matters

In order of real-world impact: daily total dwarfs everything; distribution (3–5 doses of 20–40 g) beats one giant dinner because each dose triggers its own synthesis wave; the famous post-workout “anabolic window” is far more forgiving than gym lore claims — a couple of hours either side of training is fine, especially if you trained fed; and pre-sleep protein (~30–40 g, classically casein or yogurt) shows modest extra overnight synthesis in trained people. Breakfast is where most people’s distribution fails — a coffee-and-toast morning wastes a synthesis slot that eggs or yogurt would fill.

Protein supplements: when powder earns its place

Protein powder is a convenience, not a requirement — food covers most targets. It earns its place when targets are high and schedules are real: post-training when a meal is hours away, travel days, low appetites, plant-based diets pushing 2 g/kg. Quick honest guide: whey absorbs fast and carries the best leucine content; casein digests slowly (the pre-sleep pick); soy and pea/rice blends serve plant-based users well. Look for third-party tested products, treat “mass gainers” as expensive calories, and remember powder counts toward the same daily total — it adds nothing beyond the grams.

High-protein diets: benefits and honest cautions

The benefits are well documented: stronger satiety per calorie, a higher thermic cost of digestion, and muscle preservation in a deficit — the reasons high-protein approaches keep outperforming in weight-loss trials. The honest caveats: above ~2.2 g/kg the extra benefit flattens for almost everyone; protein displaces other foods, so fibre and micronutrients need active protection; very high intakes raise hydration needs; and the kidney caution from earlier stands — established kidney disease changes the rules entirely. High-protein is a tool with a broad safe range, not an arms race.

Using your protein target safely

A protein target is a wellness guideline, not a prescription. Check with a doctor or registered dietitian before making big changes if you have kidney or liver disease, diabetes, are pregnant or breastfeeding, or have a history of disordered eating. Unintentional weight or muscle loss deserves a medical review, not just more protein.

Frequently asked questions

How much protein should I eat a day?

Most adults do well between 1.2 and 2.0 grams per kilogram of body weight — roughly 84 to 140 g for a 70 kg person. The right point in that range depends on how much you train and whether you are cutting, maintaining or building muscle.

Is the RDA of 0.8 g/kg enough?

It prevents deficiency, but it is a minimum for sedentary people rather than an optimum. Anyone who exercises, is dieting, or is over 65 benefits from more.

How much protein do I need to build muscle?

The evidence supports 1.6–2.2 g per kilogram of body weight daily, combined with resistance training and enough total calories. More than that produces little extra growth.

How much protein per meal can my body use?

Around 20–40 g per meal maximally stimulates muscle protein synthesis. Larger amounts are not wasted — they still count toward your day — but spreading protein across 3–5 meals uses it most efficiently.

Is too much protein bad for your kidneys?

In people with healthy kidneys, research has not shown harm at intakes up to and beyond 2 g/kg. In people with existing kidney disease, protein intake genuinely matters and should be set with a physician.

Do protein needs change with age?

Yes — older adults process protein less efficiently and lose muscle faster, so most experts recommend 1.0–1.2 g/kg after about age 65, ideally paired with strength training.

How many protein shakes a day is okay?

One or two is entirely reasonable when food alone doesn’t reach your target — powder is just concentrated food protein. Getting most protein from whole foods remains the better default for fibre and micronutrients.

Is protein before bed useful?

Modestly, for people who train: ~30–40 g of slow protein (casein, yogurt) supports overnight muscle synthesis. For everyone else, it simply counts toward the daily total.

Do I need protein on rest days?

Yes — muscle repair and growth continue for 24–48 hours after training, so rest-day protein matters as much as training-day protein. Keep the target constant.

Are eggs a good protein source — and how many is fine?

Excellent: ~6–7 g of top-quality protein each. For most healthy people, an egg or two daily fits comfortably in current cardiovascular guidance; individual lipid responses vary, which your routine blood panel will show.

Can vegetarians build muscle as effectively?

Yes — with matched protein totals and training, plant-based lifters gain comparably in studies. It requires slightly more planning (variety, ~10–15% higher targets, soy as an anchor), not different biology.