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Protein by weight & activity

Protein Calculator: Daily Protein Intake & RDA by Age

Determine optimal daily protein intake.

No personal data leaves your browser, estimates only.

01

Demographics & activity

ftin
BMI context

BMI 23.7 from height and weight. High g/kg targets merit clinician input for some body compositions.

Adds ~25 g/day each where applicable.

Shows protein as a share of energy (often 10–35%).

02

Targets & mix

Daily protein goal about 89.8 grams, about 1.2 grams per kilogram body weight. About 18 percent of 2000 kilocalories per day.

RDA benchmark

56 g/day

Minimum for men at age 35. Your goal is the higher of this and the activity-based target.

Caloric share

18% of 2000 kcal

Protein ≈ 359.2 kcal (4 kcal/g).

Macro slice (by calories)

Protein 18%

Other 82%

Source mix

Blend animal and plant proteins for amino acid coverage.

  • Skinless poultry (chicken, turkey)
  • Fish (salmon, cod, tuna)
  • Beans, lentils, chickpeas
  • Tofu, tempeh, edamame
  • Eggs
  • Greek yogurt, cottage cheese
  • Lean beef or pork (trimmed)
  • Nuts and seeds

What are proteins?

Proteins build tissue and act as enzymes and messengers. Nine amino acids are essential in the diet. This tool scales weight, activity, and state to a daily gram target (RDA floor, up to ~2 g/kg for very intense activity).

How much do I need?

Sedentary adults often cite ~0.8 g/kg; active people may use 1.2–2.0 g/kg. Pregnancy and lactation add ~25 g/day each. Compare your goal to total calories (commonly 10–35% from protein).

Protein Calculator: Nitrogen Balance & Your Intake

Protein isn't one number, it's a range that depends on your weight, activity, and life stage. These insights explain why the RDA is a floor, why athletes need more, and how to use the calculator without overthinking. If you enter total daily calories, you also see protein as a share of that full day, whether you are near maintenance or eating in a deficit.

Protein Intelligence

The Role of Proteins

Proteins support structure, immunity, and metabolism, they're not just for muscle.
The calculator turns your weight and activity into a daily gram target so you can meet needs without guessing. Who it's for: anyone asking "how much protein do I need?" for general health, weight loss, or muscle gain.

Why the RDA Is a Floor, Not a Ceiling

The RDA (0.8 g/kg) is the minimum to prevent deficiency for sedentary adults.
Active people, athletes, and those pregnant or lactating need more. The calculator scales from 0.8 to 2.0 g/kg and adds pregnancy/lactation bumps, your goal is the higher of the RDA and your activity-based target.

Amino Acid Architecture

Quality matters: complete proteins supply all nine essential amino acids; others can be combined (e.g. beans + grains).
Use the "Prioritize" list for higher-quality sources and the "Limit" list to cut back on processed or fried options.

Pro/Athlete Mode & Safe Zone

Turn on Pro/Athlete Mode to set a custom protein target (e.g. per kg or per lb).
The Safe Zone indicator turns yellow above 2.5 g/kg, a common upper bound; discuss higher intakes with a provider. The macro chart shows protein as a share of your total calories (1 g protein = 4 kcal). With total daily calories filled in, that percentage reflects your full energy budget for the day.

Protein Calculator: Daily Protein Intake & RDA by Age

Free protein calculator: daily protein goal by weight and activity. How much protein to build muscle, intake for weight loss or pregnancy, RDA by age. Add total calories to see protein as a share of maintenance or deficit goals.

What This Protein Calculator Does

Calculator Purpose & Outputs

This protein calculator gives a daily protein goal (grams) from body weight, activity level, and physiological state (pregnancy, lactation). It uses the RDA (0.8 g/kg) as a baseline and scales up to 2.0 g/kg for very intense activity. Outputs: daily protein goal, RDA benchmark by age/sex, caloric contribution (protein as % of total calories when you enter daily calories), and an optimal source mix. Pro/Athlete Mode supports a custom target (per kg or per lb) with a Safe Zone indicator and macro chart.
  • What You'll Get:

    Daily Protein Goal: Grams per day (0.8–2.0 g/kg by activity, plus ~25 g for pregnancy or lactation). Ranges from about 56 g (sedentary 70 kg adult) to 150+ g (very active or pregnancy).

    RDA Benchmark: Minimum to prevent deficiency, e.g. 56 g/day for men 19–70+, 46 g for women (RDA of protein by age). Your goal is the higher of this and your activity-based target.

    Caloric Contribution: With total daily calories entered, protein is shown as a percentage (typically 10–35% of energy).

    Optimal Source Mix: Prioritize list (skinless poultry, fish, beans, tofu, eggs) vs limit list (processed meats, fried meats).

  • How Protein Is Calculated:

    Base: RDA 0.8 g/kg body weight. Activity: Sedentary 0.8, Light 1.0, Moderate 1.2, Very Active 1.5, Very Intense 2.0 g/kg. Pregnancy/Lactation: +25 g each. Daily goal = max(weight_kg × factor + pregnancy/lactation add, RDA by age/sex). RDA by age: 9–13: 34 g; 14–18 M: 52 g F: 46 g; 19+: M 56 g F 46 g.

  • Ideal Users:

    How much protein do I need to build muscle? Select Very Active or Very Intense for 1.5–2.0 g/kg targets.

    Daily protein intake for weight loss: Enter total calories to see protein as % of intake; aim for 1.2–1.6 g/kg to preserve muscle.

    Already have a calorie target: Enter total daily calories to see whether your protein goal lines up with maintenance, a deficit, or a surplus as a percentage of that day.

    Protein requirements for pregnancy: Use Pregnant or Lactating for +25 g each.

    RDA of protein by age: The tool shows the RDA minimum by your age and sex.

    Vegan/plant-based: Use the Prioritize list; aim for the upper range for digestibility.

  • Accuracy & Limitations:
    Targets are general guidelines, not medical advice. People with kidney disease or diabetes may need different intakes, discuss with your provider.

How the Math Works

Activity-Scaled Protein Formula

The calculator computes a daily protein goal from body weight and an activity-based multiplier:
Pbase=Wkg×factivityP_{\text{base}} = W_{\text{kg}} \times f_{\text{activity}}

where Wkg is body weight in kilograms and factivity is the activity factor. The final goal accounts for life stage and the RDA floor:

Pgoal=max⁡ ⁣(Pbase+Ppregnancy+Plactation,  RDAage,sex)P_{\text{goal}} = \max\!\big(P_{\text{base}} + P_{\text{pregnancy}} + P_{\text{lactation}},\; \text{RDA}_{\text{age,sex}}\big)
  • factivity values:
    Sedentary: 0.8 g/kg | Light: 1.0 | Moderate: 1.2 | Very Active: 1.5 | Very Intense: 2.0 g/kg
  • Pregnancy add:
    +25 g/day when Pregnant toggle is on
  • Lactation add:
    +25 g/day when Lactating toggle is on
  • RDA floor:
    Age 9–13: 34 g; 14–18: M 52 g / F 46 g; 19+: M 56 g / F 46 g

Protein as Percentage of Calories

When you enter total daily calories, the calculator shows protein as a share of energy intake:
Protein %=Pgoal×4 kcal/gTotal Daily Calories×100%\text{Protein \%} = \frac{P_{\text{goal}} \times 4\text{ kcal/g}}{\text{Total Daily Calories}} \times 100\%

The acceptable macronutrient distribution range (AMDR) for protein is 10–35% of total calories. Values outside this range may warrant discussion with a provider.

  • 4 kcal/g:
    Energy density of protein (and carbohydrates); fat provides 9 kcal/g
  • AMDR Range:
    10–35% of calories from protein is the general adult recommendation

Worked Example

70 kg male, age 30, "Very Active" level, 2,400 kcal/day target.

  • Base protein: 70 × 1.5 = 105 g/day
  • RDA floor (male 19+): 56 g/day
  • Goal: max(105, 56) = 105 g/day
  • Caloric contribution: (105 × 4) / 2400 = 420 / 2400 = 17.5% of calories

This falls within the 10–35% AMDR. For muscle gain, selecting "Very Intense" would yield 70 × 2.0 = 140 g/day (23.3% of 2,400 kcal).

  • Safe Zone:
    Pro/Athlete Mode shows a yellow indicator above 2.5 g/kg, a common upper bound in the literature; intakes beyond this have limited additional benefit for most people
  • Limitation, Body Composition:
    This calculator uses total body weight, not lean mass. People with high body fat percentages may get slightly inflated targets; using goal weight can partially offset this

How to Use This Calculator

Start by entering your body weight in pounds or kilograms—the calculator handles unit conversion automatically. Select your activity level from Sedentary (desk job, minimal exercise) through Very Intense (two or more hours of elevated heart rate daily, or a physical job plus dedicated training). Each level corresponds to a protein multiplier between 0.8 and 2.0 grams per kilogram of body weight. Enter your age and sex so the RDA benchmark for your demographic appears alongside your personalized goal.
  • Pregnancy / Lactation Toggles:
    Switch either or both on to add approximately 25 g each to your activity-based target, reflecting increased physiological demand during pregnancy and breastfeeding.
  • Total Daily Calories (optional):
    Enter your calorie target to see protein as a percentage of total energy. The acceptable macronutrient distribution range is 10–35% of calories; values outside this range may warrant a conversation with a provider.
  • Pro/Athlete Mode:
    Enable this toggle to set a custom per-kg or per-lb protein target. The Safe Zone gauge turns yellow above 2.5 g/kg. A macro chart displays protein as a share of your total daily calories.
  • Reading Your Results:
    The dashboard shows your daily protein goal in grams, the RDA floor for your age and sex, the caloric contribution percentage, and the optimal source mix with Prioritize and Limit lists to guide food choices.

When GLP-1 meds quiet your appetite but protein still matters

This tool answers a narrow question: given your weight, activity, and life stage, how many grams of protein should you bank on per day? That's still the right anchor if you're losing weight and trying to hold onto muscle.

GLP-1 medicines (semaglutide, tirzepatide, and the brands people actually ask about by name, like Ozempic, Wegovy, Mounjaro, or Zepbound) often shrink appetite. Smaller meals make it easier to fall short on protein even when the math says you still need those grams. Some days you'll want your protein target sitting next to a calorie budget, not off on its own.

For that fuller picture, open our GLP-1 Macro & Calorie Calculator. It keeps protein up front but folds in calories and macros the way people tend to plan when they're on these meds. It's still not medical advice; bring any numbers to your clinician or dietitian before you change what you eat.

What Are Proteins? RDA, Essential Amino Acids & Sources

What Are Proteins?

Proteins are building blocks of body tissue: they act as antibodies, enzymes, and messengers. Twenty amino acids determine a protein's structure; nine are "essential" and must come from diet. High-quality sources (eggs, fish, soy, quinoa) provide all nine; combining plant sources (e.g. beans + grains) can meet essential amino acid needs. This protein calculator gives a daily gram target so you can meet those needs by weight and activity.
  • Essential Amino Acids:
    Nine must come from food: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine. Animal and some plant proteins (soy, quinoa) are "complete"; other plant sources can be combined for a complete profile.
  • Protein and Health Conditions:
    Protein monitoring matters for kidney disease or diabetes. Is too much protein bad for my kidneys? For healthy adults, high intake is generally not harmful; those with kidney disease should follow provider guidance. This protein calculator is for education only, not medical advice.

Protein Calculator FAQ

Is too much protein bad for my kidneys?

For healthy adults, high protein intake (e.g. 1.5–2.0 g/kg) is generally not harmful to kidneys. People with existing kidney disease or reduced kidney function may need to limit protein; your provider or dietitian will advise. If you have kidney disease or diabetes, protein monitoring can be critical, discuss your intake with your healthcare team. This protein calculator gives general targets; it is not medical advice.

How much protein for an athlete?

Athletes and very active people often need 1.6–2.0 g per kg body weight for tissue repair, muscle synthesis, and recovery. The RDA (0.8 g/kg) is a minimum for sedentary adults. This protein calculator scales your target up to 2.0 g/kg when you select "Very Intense" (2+ hours of elevated heart rate or physical job + training). How much protein do I need to build muscle? Typically 1.6–2.2 g/kg with adequate calories and resistance training.

Can I get enough protein on a vegan diet?

Yes. Plant-based proteins (beans, lentils, tofu, tempeh, soy, quinoa, nuts, seeds) can meet daily needs. Combine complementary sources to get all nine essential amino acids (e.g. beans + grains). This protein calculator gives a daily gram target; use the "Prioritize" source list for options like beans, tofu, and legumes. Vegan athletes may aim for the upper end of the range (1.6–2.0 g/kg) to account for digestibility.

How much protein do I need to build muscle?

For muscle hypertrophy, aim for about 1.6–2.2 g per kg body weight with adequate total calories and resistance training. The protein calculator scales from 0.8 g/kg (sedentary) to 2.0 g/kg (very intense). Select "Very Active" or "Very Intense" for muscle-building targets. Daily protein intake for weight loss should stay high (e.g. 1.2–1.6 g/kg) to preserve muscle while in a deficit.

What is daily protein intake for weight loss?

When losing weight, adequate protein helps preserve muscle. Aim for at least 1.2–1.6 g per kg body weight (or ~25–35% of calories). This protein calculator lets you enter total daily calories to see protein as a percentage of your energy budget (typically 10–35%). Prioritize protein-rich foods and spread intake across meals.

How much protein at maintenance vs in a calorie deficit?

At maintenance, protein needs still scale with weight and activity. In a deficit, similar per-kg targets (often about 1.2–1.6 g/kg) help preserve lean mass while you lose weight. Enter your total daily calories to see how your protein goal fits as a percentage of that full-day budget, whether you are maintaining or cutting. These are general targets, not individualized meal plans.

What are protein requirements for pregnancy?

Pregnancy increases protein needs for fetal and maternal tissue. Guidelines typically add about 25 g per day during pregnancy (and ~25 g for lactation). This protein calculator has a "Pregnant" and "Lactating" toggle that adds 25 g each to your activity-based target. Protein requirements for pregnancy vary by trimester; discuss with your provider or dietitian.

What is the RDA of protein by age?

The RDA (Recommended Dietary Allowance) of protein by age and sex: ages 9–13 about 34 g/day; 14–18 about 52 g (male) or 46 g (female); 19–70+ about 56 g (male) or 46 g (female). This protein calculator uses your age and sex to show the RDA benchmark and ensures your daily goal is at least this minimum.

Sources & citations

References used for the calculation method and definitions. Links open in a new tab when available.

[1]
Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids – IOM

IOM RDA for protein (0.8 g/kg for adults) and acceptable macronutrient distribution range (10-35% of calories).

[2]
Jäger R et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20

ISSN evidence-based recommendations for protein intake in athletes: 1.4-2.0 g/kg/day for muscle building and recovery.

Fitness Reference Note

Informational Use: These calculations (BMI, Calories, etc.) are based on standard statistical formulas and are intended for general reference and goal-setting purposes only.

Consult Experts: This tool does not provide medical advice, diagnosis, or treatment. Results may not be accurate for athletes, pregnant individuals, or those with underlying health conditions.

Health Safety: Always consult with a healthcare professional or qualified trainer before beginning any new diet or intensive exercise program.

Privacy First: All calculations are performed locally in your browser. No health data is stored or transmitted to any server.

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