Protein Calculator

How Much Protein Do You Need?

Protein requirements vary significantly based on your activity level, body composition goals, and overall health. The Recommended Dietary Allowance (RDA) of 0.8 g/kg is the minimum to prevent deficiency — not the optimal amount for active people.

The International Society of Sports Nutrition (ISSN) recommends 1.4–2.0 g/kg/day for physically active individuals to optimize training adaptations and body composition. Research consistently shows higher protein intake supports muscle protein synthesis, recovery, and satiety during weight loss.

Protein Intake by Goal

The following table shows recommended protein ranges for different goals, with an example calculation for a 70 kg (154 lb) individual.

Which Range Applies to You

Picking the multiplier matters more than the arithmetic. Choose the wrong one and a perfectly executed calculation hands you a number you don't need. Below are the ranges as the major position statements define them, each with the population it targets. If you want the longer version, we cover it in how much protein you need per day.

Sedentary adults — 0.8 g/kg

The 0.8 g/kg figure comes from the US Institute of Medicine's 2005 Dietary Reference Intakes; EFSA landed on 0.83 g/kg in 2012. It's the amount that keeps 97.5% of healthy adults out of nitrogen deficit, derived from balance studies in people who don't train. A floor for avoiding deficiency, then, and nobody set it as a performance target.

Generally active — 1.2 to 1.6 g/kg

Two or three gym sessions a week, or a job that keeps you on your feet all day. The ISSN position stand (Jäger et al., 2017) puts physically active people at 1.4–2.0 g/kg. For a 75 kg adult that's 105–150 g a day against 60 g at the RDA. Training raises protein turnover, and nobody ever measured the RDA in people who train.

Building muscle — 1.6 to 2.2 g/kg

Morton et al. (2018) pooled 49 resistance-training studies in the British Journal of Sports Medicine and found gains in lean mass stopped improving past roughly 1.6 g/kg. Their confidence interval reached 2.2 g/kg, which is why the upper figure survives as a hedge. Eating 3 g/kg won't harm a healthy adult; it just buys nothing the training doesn't already deliver. Pair the intake with a plan like the one in our body recomposition guide.

Dieting in a deficit — 1.6 to 2.4 g/kg

A deficit asks protein to do two jobs: hold onto lean mass while calories are short, and keep hunger manageable. Helms et al. (2014) reviewed lean athletes cutting for competition and recommended 2.3–3.1 g per kg of fat-free mass, which at 15% body fat works out near 2.0–2.6 g/kg of scale weight. The leaner you get, the higher inside that band you belong. Someone starting a diet at 30% body fat does not need the top of it.

Adults over 65 — 1.2 to 1.5 g/kg

Older muscle responds less to the same dose of protein, a blunting researchers call anabolic resistance. The PROT-AGE study group (Bauer et al., 2013) recommends 1.0–1.2 g/kg for healthy people over 65, rising to 1.2–1.5 g/kg for those who exercise or are recovering from illness. ESPEN's guidance (Deutz et al., 2014) reaches the same place. Both stress 25–30 g per meal rather than one large evening serving. Our notes on tracking after 40 cover the practical side.

On GLP-1 medication — 1.2 to 1.5 g/kg

Semaglutide and tirzepatide suppress appetite hard, and the body-composition sub-study of STEP 1 (Wilding et al., 2021) recorded lean mass falling alongside fat mass. Obesity-medicine guidance (Almandoz et al., 2024, Obesity) advises protein at the upper end of the general range together with resistance training. Reaching that number on a suppressed appetite is the hard part, which is why protein usually has to be the first thing on the fork. We go deeper in protein targets on GLP-1 medication, muscle loss on GLP-1 drugs and a practical GLP-1 food list. Follow the plan your prescriber or dietitian sets; nothing here is medical advice.

Goal Weight or Current Weight?

Multiplying by scale weight is where protein maths breaks most often. Adipose tissue holds very little protein and turns over slowly, so a kilogram of fat doesn't create the demand a kilogram of muscle does. At 140 kg, 1.6 g/kg reads as 224 g of protein a day. That's about 900 kcal before anything else reaches the plate, and more than most people will eat willingly for long.

Clinical dietitians work around this with adjusted body weight. Ideal weight comes from the Devine formula (45.5 kg plus 2.3 kg for every inch above 5 ft for women, 50 kg plus 2.3 kg for men), then 40% of the excess goes back on: ABW = IBW + 0.4 × (actual weight − IBW). The 40% accounts for the lean tissue that comes with carrying extra mass, because heavier bodies do build muscle to move themselves around.

Worked through: a woman of 165 cm weighing 118 kg has an ideal weight near 57 kg. Her adjusted weight is 57 + 0.4 × 61, or 81 kg. At 1.5 g/kg that's 122 g of protein a day instead of the 177 g her scale weight implies. One of those targets fits across three meals. The other doesn't.

The calculator above multiplies whatever number you type into it. If your BMI sits above roughly 30, enter your adjusted weight rather than your scale weight. If you already have a body-fat estimate, run the lean body mass calculator and apply 1.6–2.4 g per kg of lean mass instead.

What 131 g Looks Like on a Plate

Marta weighs 82 kg (181 lb), lifts three times a week and is eating in a deficit. At 1.6 g/kg her target is 131 g a day. Spread across four eating occasions that's roughly 33 g each, which is the number worth memorising, because it turns a daily total into a decision you make per plate.

The day lands two grams over target. Protein supplies 532 kcal of it, around a third of the energy in those four items. Nothing on the list is expensive or hard to find. Swap the salmon for 125 g of 5% beef mince and the protein holds near 33 g while the calories drop by about 130.

A plant-based version restructures rather than substituting one for one, since the densest options carry more calories per gram of protein: 200 g of cooked lentils gives 18 g, 100 g of tempeh gives 19 g, 150 g of firm tofu gives 17 g. Hitting 131 g takes more volume and usually a soy or pea powder. Eating varied sources across the day covers the amino acid profile, which we unpack in complete versus incomplete proteins.

Best Protein Sources

A mix of animal and plant proteins ensures a complete amino acid profile. Here are top sources with their protein content per serving.

Protein per Realistic Portion

Per-100 g figures suit labels and fail at the kitchen counter, where you're holding a chicken breast rather than a scale reading. These are portions people actually serve themselves, with values from USDA FoodData Central rounded to the nearest gram.

Values from USDA FoodData Central, rounded. Brands vary, so check the pack for anything processed.

Two patterns fall out of the list. Lean animal foods and whey deliver 25–46 g for 100–270 kcal, while the plant entries cost 175–330 kcal for under 20 g, which is why plant-based targets need either larger volume or a powder. And staples like rice and oats contribute five or six grams apiece: enough to matter across a day, never enough to build a meal around. For a longer list sorted by density, see our high-protein food rundown.

How to Spread It Across the Day

Muscle protein synthesis responds to a dose rather than to a daily sum. Areta et al. (2013) fed 80 g of whey after resistance exercise in three patterns and found 4 × 20 g every three hours beat both 8 × 10 g and 2 × 40 g. Mamerow et al. (2014) spread 90 g evenly across three meals and measured 24-hour synthesis about 25% higher than the usual skewed pattern of a light breakfast and a large dinner.

In practice that means 20–40 g per meal. Twenty grams saturates the response in a young adult after leg training, while Macnaughton et al. (2016) showed 40 g did more than 20 g when the session worked the whole body. Older adults sit at the top of the band for the reason described above.

Leucine explains why a threshold exists at all. It's the amino acid that switches synthesis on, and a meal needs roughly 2–3 g of it to flip that switch: about 25 g of whey protein, or 30 g of protein from chicken. Most plant sources carry less leucine per gram, so they need a bigger serving to clear the same bar. That mechanism is the whole basis of "get 30 g at breakfast" advice.

None of it outranks the daily total, though. Hit 131 g in two meals rather than four and you keep nearly all of the benefit, which makes distribution the last thing to fix rather than the first. Our piece on protein timing walks through what the post-workout research actually found.

Common Protein Myths

• "Too much protein damages your kidneys." In healthy adults, high-protein diets (up to 2.2 g/kg) show no adverse effects on kidney function. This concern applies primarily to individuals with pre-existing kidney disease.
• "Plant protein is incomplete and inferior." While individual plant sources may lack certain amino acids, eating a variety of plant proteins throughout the day easily provides all essential amino acids. You don't need to combine them in a single meal.
• "You can only absorb 30 g of protein per meal." Your body can digest and utilize far more than 30 g per sitting. Larger doses are absorbed more slowly, but virtually all dietary protein is eventually used.
• "High protein makes you bulky." Protein alone does not cause significant muscle hypertrophy — that requires progressive resistance training and a calorie surplus. Higher protein during a deficit actually helps preserve lean mass.
• "You need protein immediately after a workout." The anabolic window is much wider than once believed. Total daily protein intake matters far more than precise post-workout timing.

How Much Is Too Much?

For healthy kidneys the evidence doesn't support a ceiling anywhere near what people actually eat. Devries et al. (2018) pooled 28 trials in the Journal of Nutrition and found no effect of higher protein intakes on glomerular filtration rate in healthy adults. A one-year crossover study in resistance-trained men at 2.5–3.3 g/kg (Antonio et al., 2016) reported no change in kidney or liver blood markers over that period.

Existing kidney disease reverses the advice entirely. KDIGO's chronic kidney disease guideline recommends restricting protein, commonly to 0.6–0.8 g/kg, for people with reduced function who aren't on dialysis. If you have CKD, diabetes with kidney involvement, a transplant or a single kidney, the number on this page isn't yours to use. Your nephrologist or renal dietitian sets it, and that conversation should happen before you change anything.

For everyone else the real limit is displacement. Inside a fixed calorie budget, protein at 3 g/kg crowds out carbohydrate and fat, which costs training fuel and, if fibre-rich foods go first, comfortable digestion. Above roughly 2.2 g/kg you're paying for food that does nothing measurable. Pregnancy and any liver condition also need a clinician's number rather than a calculator's.

Protein Questions, Answered

• How much protein do I need per day? For most adults, between 1.2 and 2.0 g per kilogram of body weight. Sedentary adults meet their requirement at 0.8 g/kg, the RDA set by the US Institute of Medicine in 2005, while the ISSN recommends 1.4–2.0 g/kg for physically active people. At 70 kg that's a spread from 56 g to 140 g depending on which description fits you.
• Is 100 grams of protein a day enough? It depends entirely on your weight and what you're asking of your body. For a 60 kg person, 100 g works out at 1.67 g/kg, which covers muscle gain or a deficit. For a 95 kg person it's 1.05 g/kg, below the range for anyone lifting or dieting, though adequate for a sedentary adult. Divide 100 by your weight in kilograms and compare the result against the goal table.
• Should I calculate protein from my current weight or my goal weight? Below a BMI of about 30, current weight works fine. Above that, scale weight overstates the target, because fat tissue has little protein turnover. Dietitians use adjusted body weight: ideal weight plus 40% of the excess. A woman of 165 cm weighing 118 kg gets 122 g at 1.5 g/kg of adjusted weight rather than 177 g from her scale weight.
• Can your body only absorb 30 g of protein per meal? No. Absorption isn't the constraint, since the gut takes up nearly all the protein you eat, just more slowly at larger doses. What plateaus is muscle protein synthesis, and 20–40 g per meal saturates that response in most adults. Protein beyond the dose still goes to other tissues or gets used for energy.
• Does eating a lot of protein damage your kidneys? Not in people with healthy kidneys. Devries et al. (2018) pooled 28 trials and found no effect on glomerular filtration rate. The caution belongs to existing chronic kidney disease, where guidelines run the opposite way and recommend restriction. That number comes from a nephrologist, not from a calculator.
• How much protein should I eat on Ozempic, Wegovy or Mounjaro? Obesity-medicine guidance (Almandoz et al., 2024) places protein at the upper end of the general range, roughly 1.2–1.5 g/kg, paired with resistance training, because weight lost on these medications includes lean tissue. Appetite suppression makes the target harder to reach, so protein usually has to go on the fork first. Follow the plan your prescriber or dietitian sets.
• How much protein do older adults need? More per kilogram than younger adults, because muscle responds less to each dose. PROT-AGE (Bauer et al., 2013) recommends 1.0–1.2 g/kg for healthy adults over 65 and 1.2–1.5 g/kg for those who exercise or are recovering from illness, delivered as 25–30 g at each meal rather than in one large evening serving.
• Do I need protein powder to hit my target? No. A scoop is a convenience: 25 g of protein for 115 kcal in about thirty seconds, which is hard to match with cooking when you're short on time. Whole foods cover the same ground if you plan roughly 30 g of protein into each meal.