Free Adult Protein Calculator

Protein Calculator

Estimate a daily protein range and central planning target from body weight and your selected profile. Review grams per day, grams per pound, protein calories, per-meal amounts, and an optional current-intake comparison.

No sign-up5 Profiles Custom range U.S. & metric

Calculator

Estimate your daily protein

For adults age 18 and older. Select the profile that best matches the purpose of your estimate.

years
lb
These are planning ranges for generally healthy adults, not medical prescriptions.
g/day
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What does the protein calculator estimate?

The calculator multiplies body weight in kilograms by a selected grams-per-kilogram factor. Profiles provide a range plus a central planning target, because one exact number cannot represent every healthy adult's needs.

Daily protein (g) = body weight (kg) × protein factor (g/kg/day)

The general adult profile uses the U.S. RDA of 0.8 g/kg/day. Activity-focused profiles use broader evidence-informed ranges for generally healthy adults who train.

Understanding the protein profiles

General adult reference uses 0.8 g/kg/day. Healthy aging uses 1.0–1.2 g/kg/day. Endurance uses 1.2–1.6 g/kg/day. Strength and muscle uses 1.4–2.0 g/kg/day. Strength planning can be paired with the one rep max calculator, while the calorie-deficit profile uses a higher planning range because energy restriction can make lean-mass retention more challenging.

These profiles describe total daily intake from foods and supplements combined. Supplements are not required to reach a calculated target.

How the per-meal estimate works

The per-meal number simply divides the central daily target across the selected number of meals or substantial protein servings. It is not a biological absorption limit and does not mean every meal must contain exactly that amount.

Distribution may be useful for planning, but total daily intake, food quality, adequate energy, and consistent training remain important. The macro calculator can place the central protein target in the context of total calories, carbohydrate, and fat.

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How to use this protein calculator

  1. Choose U.S. or metric units.
  2. Enter age and current body weight.
  3. Select the profile closest to your purpose, or enter a custom range.
  4. Choose how many meals or protein servings you want to compare.
  5. Optionally enter current protein intake.
  6. Select Calculate Protein and review the complete range and central target.

Limitations and safety

This calculator does not diagnose deficiency, measure lean mass, evaluate amino-acid quality, or account for kidney function, liver function, pregnancy, recovery from illness, medication effects, or a therapeutic diet.

Very high values are not automatically better. If you have a medical condition or are considering a major dietary change, use a registered dietitian or qualified clinician for individualized guidance.

Frequently asked questions about protein

The U.S. adult reference value is 0.8 grams per kilogram of body weight per day for generally healthy adults.
A grams-per-kilogram method scales the estimate to body size and matches how many reference values and studies report protein intake.
Many exercise-nutrition sources use higher planning ranges, but training, health, energy intake, and goals affect what is appropriate.
No. It is only the daily target divided evenly across the selected number of servings.
Anyone with kidney or liver disease, pregnancy-related needs, eating-disorder care, or another medical nutrition requirement should ask a qualified professional.

Sources and methodology

The calculator separates the U.S. general adult reference from higher activity-oriented planning ranges.

Safety and scope: General education for adults only; not individualized nutrition therapy.
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