Dr. David Taylor, MD, PhD · Last reviewed July 3, 2026

Protein Intake Calculator

Enter your weight, age, and activity level, then pick a goal to see how many grams of protein you need each day — from the baseline RDA to the higher ranges research supports for building muscle or losing fat. Compare all five goals at once, see your target split across meals, and (for adults 65+) get a sarcopenia-aware adjustment most calculators miss.

Protein Intake Calculator

lb
Daily protein target
142 g/day
healthy range 116–160 g
Intensity · Build muscle
1.96 g/kg
ISSN 2017
One day of that looks like
  • 6.5 scoops of whey
  • 3.7 6 oz chicken breasts
  • 27 large eggs

For building muscle, aim for 1.6–2.2 g of protein per kg of body weight, paired with resistance training.

Protein per meal
MPS sweet spot ≈ 27 g/meal
3 meals
— g each
4 meals
— g each
5 meals
— g each
Your daily target across goals
g

Educational reference only. These are general targets for healthy adults from cited sports-nutrition and dietary-reference sources. If you have kidney disease (CKD), liver disease, or are on a protein-restricted medical diet, your target is individualized — often lower — and must be set by your physician or a renal dietitian. Pregnancy, dialysis, and some metabolic conditions also change protein needs. Talk to your clinician before making large changes.

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How to use this calculator

  1. Enter your body weight. Toggle between pounds and kilograms — the number converts automatically so your actual weight stays the same. Protein needs are calculated per kilogram of body weight.
  2. Add your age. If you're 65 or older, the calculator raises the floor of your range to preserve muscle (more on that below). Under 65 it uses the standard bands.
  3. Set your activity level. This positions your single daily target within the goal's range — a sedentary person lands near the low end, a very active person near the top.
  4. Pick your goal. The five tabs — General health, Active, Build muscle, Lose fat, Endurance — each map to a research-backed grams-per-kilogram range. Your target and range update instantly.
  5. Read the three result panels. The big number is your daily protein target in grams; the middle panel shows the grams-per-kilogram intensity and its source; the third translates the target into scoops of whey, chicken breasts, and eggs.
  6. Scan the per-meal split and the goal-comparison row to see how to spread protein across the day and how your target shifts if your goal changes. Then log what you actually eat and export a PDF.

Why this calculator is different from other protein calculators

Most protein calculators online run a single formula (usually weight × 0.36, the RDA in pounds), print one number, and funnel you toward a signup or a brand of powder. None show you the evidence behind the number, and almost none adjust for the two groups whose protein needs are most different from the average: people training hard and people over 65. Here's what this tool does differently:

  • Five evidence-cited goals, side-by-side. General health (the RDA), active, build muscle, lose fat, and endurance each map to a grams-per-kilogram range drawn from a named source — the Institute of Medicine, the ISSN position stand, and the joint Academy of Nutrition and Dietetics / ACSM / Dietitians of Canada position. The comparison row shows your target under all five at once.
  • A sarcopenia-aware adjustment for age 65+. Older adults need more protein than the RDA to slow age-related muscle loss. When you enter an age of 65 or older, the calculator raises the floor of your range to at least 1.0–1.2 g/kg, following the PROT-AGE and ESPEN expert recommendations. No other protein calculator does this.
  • Per-meal distribution, not just a daily number. Muscle protein synthesis responds to how you spread protein across the day, not just the total. The tool splits your target across 3, 4, and 5 meals and flags the roughly 0.4 g/kg per-meal amount research links to maximal muscle-building response.
  • Real-food translation. Your target is shown as scoops of whey, 6 oz chicken breasts, and large eggs — so an abstract gram number becomes a plan you can actually eat.
  • A pounds/kilograms toggle that converts correctly. Switch units and your weight is converted, not just relabeled — a small thing most tools get wrong.
  • Intake log + clinician-ready PDF. Log the protein you actually eat each day against your target, see how many days you hit it, and export a one-page PDF for a dietitian or doctor. Everything stays on your device.
  • Reviewed by a named physician. Most protein calculators are anonymous brand widgets. This one is reviewed by Dr. David Taylor, MD, PhD, with a cited source for every range.

How this calculator works (the math)

Protein needs scale with body weight, so every recommendation here is expressed as grams of protein per kilogram of body weight per day (g/kg). If you enter your weight in pounds, it's converted to kilograms first (1 kg ≈ 2.2 lb). Your goal sets a range, and your activity level picks a single target within that range.

The baseline: the RDA (0.8 g/kg)

The Recommended Dietary Allowance for protein is 0.8 g/kg — the amount that meets the needs of most healthy, sedentary adults. It's a floor to prevent deficiency, not an optimum for people who train. For a 68 kg (150 lb) adult that's about 54 g/day.

Active and endurance (1.2–1.6 g/kg)

Once you exercise regularly, protein needs rise. The joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine puts athletes in a 1.2–2.0 g/kg band, with recreationally active adults and endurance athletes near the lower half:

  • Active / Endurance = 1.2–1.6 g/kg

Source: Thomas DT, Erdman KA, Burke LM. Nutrition and Athletic Performance. J Acad Nutr Diet 2016;116(3):501–528.

Building muscle (1.6–2.2 g/kg)

To maximize gains in muscle mass with resistance training, the International Society of Sports Nutrition recommends a higher intake, generally in the 1.6–2.2 g/kg range:

  • Build muscle = 1.6–2.2 g/kg

Source: Jäger R, et al. ISSN Position Stand: protein and exercise. J Int Soc Sports Nutr 2017;14:20.

Losing fat while keeping muscle (1.6–2.4 g/kg)

In a calorie deficit, higher protein protects the muscle you'd otherwise lose. The ISSN notes that intakes toward the upper end — and, for lean athletes in aggressive deficits, higher still — best preserve lean mass while dieting:

  • Lose fat = 1.6–2.4 g/kg (assumes a calorie deficit plus resistance training)

Older adults: the sarcopenia-aware floor (≥ 1.0–1.2 g/kg)

After about age 60, muscle becomes more resistant to the muscle-building signal from protein (a phenomenon called anabolic resistance), and the 0.8 g/kg RDA is widely considered too low to prevent sarcopenia. The PROT-AGE Study Group and ESPEN recommend at least 1.0–1.2 g/kg for healthy older adults, and more with illness:

  • If age ≥ 65: range floor raised to 1.0 g/kg, upper to at least 1.2 g/kg

Sources: Bauer J, et al. PROT-AGE. J Am Med Dir Assoc 2013;14(8):542–559; Deutz NE, et al. ESPEN expert group. Clin Nutr 2014;33(6):929–936.

From range to a single target

Your range is weight × the goal's low and high factors. Your single target sits inside that range based on activity level — sedentary lands near the bottom, very active near the top. Numbers are rounded to whole grams.

Three real-world examples

A 68 kg lifter building muscle

A very active 25-year-old who weighs 68 kg (150 lb) and picks Build muscle gets a range of 109–150 g/day and a target near the top — about 143 g — because their activity level is high. Split across four meals that's roughly 36 g each, comfortably above the ~27 g (0.4 g/kg) per-meal amount that maximizes the muscle-building response.

A 180 lb adult in a fat-loss phase

An 82 kg (180 lb) person dieting with resistance training and choosing Lose fat gets a range of 131–196 g/day with a moderate-activity target around 170 g. That's far above the RDA — deliberately, because protein is the macronutrient that most protects lean muscle while you're eating at a deficit. Pairing it with a fiber supplement helps with the fullness a higher-protein diet is known for.

A 70-year-old focused on staying strong

A sedentary 64 kg (140 lb) 70-year-old on the General health tab would get only ~51 g from the raw RDA — but the calculator's sarcopenia-aware floor raises the range to 64–76 g/day (1.0–1.2 g/kg) with a target near 65 g. That extra protein, spread across the day and paired with any resistance activity, is exactly what the PROT-AGE guidance is designed to encourage. Older adults also absorb less vitamin B12 from food, so it's a useful companion to check.

Protein timing: does it matter when you eat it?

The single biggest lever is your total daily protein — hit your target and you've done most of the work. But distribution matters at the margins. Muscle protein synthesis is stimulated meal by meal, and each stimulus is maximized at roughly 0.4 g/kg per meal (about 20–40 g for most people). Eating three or four protein-containing meals spaced through the day generally beats loading it all into one, especially if you're training. The per-meal panel in the calculator shows you exactly what that looks like at your target. The old "anabolic window" idea — that you must eat protein within 30 minutes of training — has largely not held up; the practical takeaway is to get a normal protein meal within a few hours on either side of a workout.

Is all protein the same? Animal vs. plant

Protein quality comes down to two things: the amount of the amino acid leucine (the main trigger for muscle protein synthesis) and how digestible the protein is. Animal proteins — whey, eggs, dairy, meat, fish — are "complete," leucine-rich, and highly digestible, which is why the food translations in this tool use them as the yardstick. Plant proteins can absolutely meet the same targets, but they're generally lower in leucine and slightly less digestible, so plant-based eaters do well to aim for the higher end of their range and combine sources (for example legumes plus grains) across the day. A quality collagen supplement is a useful add-on for skin, joints, and connective tissue, though it's low in leucine and shouldn't be counted as your main muscle-building protein.

Frequently asked questions

How much protein do I need per day?

It depends on your weight and goal. The baseline RDA is 0.8 g per kilogram of body weight (about 0.36 g per pound) — roughly 54 g for a 150 lb adult. Active people need 1.2–1.6 g/kg, those building muscle 1.6–2.2 g/kg, and people losing fat while training 1.6–2.4 g/kg. Enter your details above to see your exact number.

Is 100 grams of protein a day enough?

For a smaller or sedentary adult, 100 g may be more than enough — it's around 1.5 g/kg for a 150 lb person, which sits in the active-to-muscle range. For a larger person or someone building muscle, 100 g could be too little: a 200 lb lifter targeting 1.8 g/kg needs about 165 g. Use your body weight and goal to know for sure rather than a round number.

Can too much protein be harmful?

In healthy people, protein intakes up to about 2 g/kg (and higher for athletes) have a strong safety record and don't harm the kidneys. The important exception is anyone with existing kidney disease, liver disease, or on a medically prescribed protein-restricted diet — for them a high intake can be harmful, and their target should be set (often lower) by a physician or renal dietitian. Very high intakes can also crowd out other nutrients if they dominate the diet.

Do older adults need more protein?

Yes. Aging muscle responds less strongly to protein, so the 0.8 g/kg RDA is generally too low for adults over 65. Expert groups (PROT-AGE, ESPEN) recommend at least 1.0–1.2 g/kg, and up to 1.2–1.5 g/kg during illness or recovery. This calculator applies that higher floor automatically when you enter an age of 65 or older.

Should I count protein from supplements or only food?

Count all of it. Whey, casein, and plant protein powders are just concentrated food — a scoop of whey (~24 g) counts toward your target exactly like a chicken breast does. Most people hit their target most easily with a food-first approach and one or two shakes to fill the gaps, especially on busy or training days.

Can I embed this calculator on my own site?

Yes — copy the embed snippet at the bottom of this page. The embedded version is a streamlined variant for dietitians, trainers, gyms, and health educators. Required attribution is built in. There's no fee, no signup, and no analytics attached.

Hitting a protein target is a food-first job, but a few supplements make it easier and cover the gaps a higher-protein diet can leave. Each links to the full review with current top picks, prices, and pros and cons:

  • Best Collagen Supplements — connective-tissue and skin protein that complements your daily intake (though it's low in leucine, so it's an add-on, not your main protein).
  • Best Electrolyte Powders — replace the sodium and potassium you sweat out on training days, which is when protein needs are highest.
  • Best Fiber Supplements — higher-protein diets often run low on fiber; this closes the gap and adds to the fullness protein already provides.

Sources & methodology

This tool is reviewed annually for citation currency. About Dr. Taylor · Last reviewed July 3, 2026.

Embed this tool on your site

Free for dietitians, personal trainers, gyms, and health educators. Required attribution is included in the snippet. No fee, no signup, no analytics attached to the embed. 

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  Protein intake calculator by
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  &middot; Reviewed by Dr. David Taylor, MD, PhD
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