How much protein do I need per day in grams?

Your daily protein target depends on your goal, not just your weight. A sedentary adult only needs the RDA of 0.8 g per kg of body weight (about 58 g for a 160-lb person). General recreational fitness pushes that to 1.2-1.6 g/kg. Building muscle (hypertrophy) puts the optimal range at 1.6-2.2 g/kg per the Morton et al. 2018 meta-analysis. Cutting in a calorie deficit needs even more — 2.2-3.0 g/kg per Helms et al. — to preserve lean mass. Elderly adults aiming to prevent sarcopenia should sit at 1.0-1.5 g/kg, and pregnant women in the second or third trimester need 1.1-1.5 g/kg. Our calculator picks the right range for your goal and converts it into total grams per day.

What is the leucine threshold and why does it matter?

Leucine is the branched-chain amino acid that triggers muscle protein synthesis (MPS) via the mTOR pathway. Each meal needs roughly 2.5-3 g of leucine — which works out to about 0.3-0.4 g of total protein per kg of body weight — to maximally activate MPS. Below that threshold the meal still contributes amino acids for general repair, but the anabolic spike is blunted. That is why splitting your daily total across 3-5 evenly-sized meals consistently outperforms eating one giant 100-g protein dinner. Our per-meal stacked bar shows you the threshold marker and flags any split that drops below it.

Do vegans need more protein than omnivores?

Yes, by about 20-25%. Most plant proteins (oats, rice, wheat, lentils) are lower in one or more essential amino acids — most often lysine or methionine — which lowers their digestible indispensable amino acid score (DIAAS). Whey isolate and whole egg score 100 on the reference scale; soy and pea sit around 73-91; oats are about 57; wheat is around 45. To compensate, vegans simply eat more total protein (the calculator multiplies your goal-based number by 1.22 for vegans, 1.10 for vegetarians) and combine sources like rice + pea or beans + grains so every meal hits a complete amino acid profile.

What is the difference between RDA and EAR?

The RDA (Recommended Dietary Allowance) of 0.8 g/kg is the amount that meets the needs of 97.5% of healthy adults — it includes a safety factor of about 1.25 above the underlying EAR (Estimated Average Requirement) of roughly 0.66 g/kg. The EAR is the median requirement and meets only 50% of the population. The RDA is what dietary guidelines publish; the EAR is closer to true biological need. Importantly, both are nitrogen-balance floors derived from sedentary adults — they say nothing about optimal intake for muscle gain, recovery, or aging, which is why athletes routinely consume 2-3x the RDA without any kidney or bone concern in healthy individuals.

Should I use body weight or lean body mass to calculate protein?

For lean and normal-weight people (under about 20% body fat for men, 30% for women), total body weight is fine and is what every peer-reviewed paper uses. For people with significant excess body fat, calculating off lean body mass (fat-free mass) avoids overshooting because body fat does not need protein. The practical rule from Helms et al.: if you are above 30% body fat, calculate protein off lean mass and add about 10% for safety. Our calculator has a Use Lean Mass toggle for exactly this case — toggle it on and enter your body fat percentage and the math automatically shifts to fat-free mass.

Can you eat too much protein?

For healthy kidneys, no — every controlled trial up to 4.4 g/kg/day (well above any practical intake) has shown zero adverse effects on renal function, bone density, or hydration. The myth that protein damages kidneys comes from research in people who already have moderate-to-severe kidney disease, where protein restriction is appropriate. For everyone else, the only real downside of overdoing protein is opportunity cost: every gram of protein crowds out carbs or fat, so eating 300 g a day when you optimally need 180 g just means you missed out on energy or essential fatty acids. The calculator pegs your number to the published evidence-based upper range so you do not overshoot.

How should I split protein across meals?

Aim for 3-5 evenly-spaced feedings per day, each containing 0.3-0.4 g of protein per kg of body weight. For a 180-lb (82 kg) lifter targeting 160 g/day, that means 32-40 g of protein per meal across 4-5 meals. Research from Schoenfeld and Aragon shows that going below the per-meal leucine threshold (about 25-30 g of high-quality protein, more for plant sources) leaves muscle protein synthesis on the table. Going above 40-50 g per meal does not blunt absorption — your body uses what it needs and oxidizes the rest — but it gives diminishing anabolic returns. Pre-bed casein or Greek yogurt is a useful add-on if you are training hard.

How much protein do elderly adults need?

PROT-AGE and ESPEN expert groups now recommend 1.0-1.2 g/kg for healthy older adults and 1.2-1.5 g/kg for those with acute or chronic disease — roughly 25-90% above the standard 0.8 g/kg RDA. The reason is anabolic resistance: aging skeletal muscle needs a stronger leucine signal per meal (about 35-40 g of high-quality protein, versus 25-30 g for young adults) to fully activate MPS. Combined with resistance training, hitting that target preserves muscle mass and dramatically reduces fall and frailty risk. The calculator Elderly preset uses the 1.0-1.5 g/kg band by default.

Is protein quality important or only total grams?

Both. For omnivores eating mostly animal protein, hitting your total grams target is usually enough because animal sources score near 100 on DIAAS. For plant-based eaters, quality matters: you need either complete plants (soy, quinoa, buckwheat) or smart combinations like rice + beans or pea + rice to cover all nine essential amino acids. Our protein quality panel shows scores ranging from 100 (whey, egg) down to 45 (wheat), and the calculator automatically increases your total target by 22% for vegans to compensate for lower per-gram quality. Coaches working with athletes also factor in leucine content specifically, since leucine is what fires MPS.

How much protein do pregnant women need?

Updated indicator amino acid oxidation (IAAO) studies from Stephens & Elango (2015) show pregnancy protein needs are far higher than the old RDA suggests. The IOM RDA of 1.1 g/kg/day is a floor — the IAAO data suggest 1.2 g/kg in trimester one, 1.32 g/kg in trimester two, and up to 1.52 g/kg in trimester three. Lactation requires an additional 15-20 g per day on top of pre-pregnancy needs. Quality matters too: animal protein, soy, or quinoa easily covers requirements; vegan moms-to-be should add 20-25% extra grams and prioritize legume + grain combinations to cover lysine and methionine.

Should I count protein from all foods or just animal sources?

Count every gram. Your daily total includes the protein from your oats at breakfast, the beans in your salad, the bread in your sandwich, and the chickpeas in your hummus — not just the chicken or whey shake. Most lifters underestimate plant protein contribution by 20-40 g/day. To track accurately, log everything you eat for 2-3 weeks in an app like MacroFactor or Cronometer, then compare the total to the target this calculator produces. After a few weeks of logging you will be able to eyeball portions and stay within 10% of target without active tracking.

Does protein timing around workouts really matter?

The old anabolic window of 30-60 minutes post-workout has been mostly debunked. Modern research (Aragon & Schoenfeld review) shows the relevant window is closer to 4-6 hours around the training session — a pre-workout meal 1-3 hours before training is enough to keep amino acids elevated through the session and into recovery. Far more important than timing is total daily protein and per-meal distribution. That said, if you train fasted, having 25-40 g of high-quality protein within an hour after lifting does provide a real (if small) MPS boost. The calculator focuses on the bigger lever: total daily grams plus per-meal split.

Protein Intake Calculator

Free daily protein intake calculator. Choose your goal — sedentary RDA, general fitness, hypertrophy, cutting, elderly, or pregnancy — and get exact grams per day, a per-meal split with the leucine threshold marker, and a quality score by source. Backed by Morton et al. 2018 and Helms et al. 2014 evidence ranges.

Goal Presets

7 Evidence-Based

Units

kg + lbs

Per-Meal Split

Leucine Marker

Quality Score

DIAAS-based

Your Profile

Biological Sex

Age

yrs

Unit System

Body Weight

lbs

Activity Level

Goal

Plateau for muscle protein synthesis. Going above 1.6 g/kg adds little, but staying near 2.0 g/kg gives margin for error.

Citation: Morton et al. 2018 meta-analysis (BJSM)

Diet Pattern

Vegan and vegetarian targets auto-adjust upward (+22% / +10%) for lower DIAAS protein quality.

Calculate off lean body mass (recommended > 25% body fat)

Meals per day: 4

3456

Your Protein Plan Awaits

Pick your goal, enter your weight, and hit Calculate. You'll see total daily grams, a per-meal stacked bar with the leucine threshold marker, and a quality-scored source list.

Why Daily Protein Matters: Turnover and MPS

Every cell in your body is in constant protein turnover— old, damaged proteins are broken down and new ones are built every minute of every day. The total daily flux is enormous: an average 80 kg adult turns over roughly 280 grams of protein per day, far more than the 60-200 grams most people eat. The body recycles most of those amino acids, but a portion is oxidized for energy, excreted as urea, or lost through skin, hair, and gut shedding. Your daily protein intake replaces that loss and provides the raw material for any net tissue gain.

The key adaptive mechanism is muscle protein synthesis (MPS). Each protein-containing meal triggers a roughly 3-4 hour rise in MPS through activation of mTORC1, with the branched-chain amino acid leucine acting as the primary signal. Below about 2.5-3 grams of leucine per meal — roughly 0.3-0.4 g of total protein per kg of body weight — the MPS spike is blunted; above that threshold the response saturates and additional grams get oxidized. This is why splitting your daily total across 3-5 evenly-sized meals consistently outperforms eating one giant 100-gram protein dinner: every meal that crosses the leucine threshold gives you a fresh anabolic pulse, and the day's synthesis adds up.

Protein quality matters because not all sources hit that threshold at the same dose. Whey isolate and whole egg are the gold-standard references (DIAAS = 100). Lean beef, fish, and chicken sit at 89-92. Soy is the only complete plant source (about 91); rice, oats, and wheat are limited in lysine or methionine and score 45-65. That is why vegan diets need 20-25% more total protein and smart combinations like rice + pea. The bottom line: the RDA of 0.8 g/kg is a nitrogen-balance floor for sedentary adults, not a target. Modern evidence from Morton (2018), Helms (2014), Phillips (2016), and PROT-AGE puts the optimal range at 1.6-2.2 g/kg for muscle gain, 2.2-3.0 for cutting, 1.0-1.5 for elderly adults, and 1.1-1.5 for pregnant women. This calculator picks the right range, adjusts for diet pattern, and breaks the daily total into per-meal feedings that respect the leucine threshold.

Related Calculators

Macro Calculator

Get protein, carbs, and fat split for your goal and TDEE.

Carb Intake Calculator

Time carbs around training for performance and recovery.

Fat Intake Calculator

Lock in essential fat minimums and hormone-supporting ranges.

Lean Body Mass Calculator

Convert body weight + body fat into fat-free mass for protein math.

Selected Goal

Hypertrophy / Muscle Gain

1.6-2.2 g/kg

Plateau for muscle protein synthesis. Going above 1.6 g/kg adds little, but staying near 2.0 g/kg gives margin for error.

Citation: Morton et al. 2018 meta-analysis (BJSM)

How to Set Your Protein Target in 5 Steps

A simple workflow used by registered dietitians, hypertrophy coaches, and natural bodybuilding prep teams.

Weigh in honestly

Step on the scale first thing in the morning after using the bathroom. Use the lighter clothing you wear every weigh-in for consistency.

Pick the right goal

Sedentary RDA is the floor. Hypertrophy 1.6-2.2 g/kg for muscle gain. Cutting 2.2-3.0 g/kg if dieting hard. Elderly 1.0-1.5. Pregnancy 1.1-1.5.

Adjust for diet quality

Vegans add 20-25%, vegetarians add 10% to compensate for lower DIAAS protein quality. Omnivores stay as-is.

Split across meals

Divide the daily total into 3-5 evenly-spaced meals. Each must clear the 0.3-0.4 g/kg leucine threshold or you blunt the MPS spike.

Track and adjust

Log everything for 2-3 weeks in MacroFactor or Cronometer. Recheck on this calculator every time body weight shifts by 3-4 lbs.

Real-World Use Cases

Four common scenarios that benefit most from a precise protein number.

Hypertrophy on a Lean Bulk

An 82 kg recreational lifter targeting muscle gain sits in the 1.6-2.2 g/kg sweet spot from Morton et al. 2018 — about 130-180 g per day, evenly split across 4 meals. Run the number here, then plug your full TDEE breakdown into the Macro Calculator to lock in carbs and fat.

Aggressive Cut Without Losing Muscle

Helms et al. recommend 2.2-3.0 g/kg in a deficit. Pair this calculator with the Carb Calculator to time carbs around lifting sessions while you keep protein high to preserve lean mass and maximize satiety.

Hormone Support While Dieting

Crushing protein without enough dietary fat tanks testosterone and disrupts cycles. After locking your protein here, head to the Fat Intake Calculator to set the minimum fat floor (0.6-0.8 g/lb for most athletes).

Obesity: Calculate Off Lean Mass

Above 25-30% body fat, calculating protein off total weight inflates the target. Use the Lean Body Mass toggle here, or get an exact number first via the Lean Body Mass Calculator and feed it back in.

Frequently Asked Questions

Have more questions? Contact us

What Coaches and Athletes Say

4.9

Based on 7,800 reviews

“I drop this calculator into every client onboarding email. The goal presets cite Morton 2018 and Helms 2014 by name, which is exactly the credibility I want when telling a new client they need 200 g of protein a day. Per-meal split is the part everyone screenshots.”

Trent Mihalek

Online Hypertrophy Coach

March 12, 2026

“Finally a protein tool that does not treat vegans as an afterthought. The 22% quality multiplier for vegan diets is exactly what the DIAAS literature supports, and the source-quality panel lets me show clients why pea-rice blends beat wheat-only seitan plans.”

Aditi Raghavan

Plant-Based Sports Dietitian

February 4, 2026

“The 1.0-1.5 g/kg elderly preset and the leucine-threshold flag are gold for working with my over-65 clientele. I send the export to their primary care doctor to defuse the kidney concern argument every single time.”

Margaret OConnor

Geriatric Strength Coach

December 21, 2025

“On prep I am running 3.0 g/kg for the last 6 weeks and this calculator nails it. The per-meal stacked bar with the leucine marker keeps me from cramming 80 g into one shake and missing the mid-day pulse. Diamond Grade tool.”

Caleb Hauser

Natural Bodybuilding Competitor

November 18, 2025

Love using our calculator?

Learn More

Dive deeper with our expert guides and tutorials related to Protein Intake Calculator

Loading articles...

Protein Intake Calculator

Your Profile

Your Protein Plan Awaits

Why Daily Protein Matters: Turnover and MPS

Related Calculators

Selected Goal

How to Set Your Protein Target in 5 Steps

Weigh in honestly

Pick the right goal

Adjust for diet quality

Split across meals

Track and adjust

Real-World Use Cases

Hypertrophy on a Lean Bulk

Aggressive Cut Without Losing Muscle

Hormone Support While Dieting

Obesity: Calculate Off Lean Mass

Frequently Asked Questions

What Coaches and Athletes Say

Related Articles

Technical Services
59 toolsPopular

Power Tools⚡

Protein Intake Calculator

Your Profile

Your Protein Plan Awaits

Why Daily Protein Matters: Turnover and MPS

Related Calculators

Selected Goal

How to Set Your Protein Target in 5 Steps

Weigh in honestly

Pick the right goal

Adjust for diet quality

Split across meals

Track and adjust

Real-World Use Cases

Hypertrophy on a Lean Bulk

Aggressive Cut Without Losing Muscle

Hormone Support While Dieting

Obesity: Calculate Off Lean Mass

Frequently Asked Questions

What Coaches and Athletes Say

Related Articles

Technical Services59 toolsPopular

Power Tools⚡

Technical Services
59 toolsPopular