How to Calculate Protein Intake: Daily Grams by Body Weight
Learn how to calculate protein intake from body weight, goals, and activity level, with simple examples and practical ways to estimate daily grams.
Searching how to calculate protein intake usually means you want a practical daily target in grams. A common way to estimate protein is by body weight.
For healthy adults, the Recommended Dietary Allowance is 0.8 grams of protein per kilogram of body weight per day, according to the U.S. Recommended Dietary Allowances. That amount is intended to cover basic needs and prevent deficiency in most adults. Active people often choose higher targets depending on training and goals.
Basic Protein Formula
Protein grams per day = Body weight in kg x Target grams per kg
If you know your weight in pounds, convert it first:
Kilograms = Pounds x 0.453592
Example
Suppose you weigh 70 kg.
- At 0.8 g/kg: 70 x 0.8 = 56 g/day
- At 1.2 g/kg: 70 x 1.2 = 84 g/day
- At 1.6 g/kg: 70 x 1.6 = 112 g/day
Picking a Target
General intake targets depend on context. A minimal target to meet basic adult needs is lower than a target chosen for training or dieting. If you are trying to maintain muscle while in a calorie deficit or training hard, people often aim above the basic RDA.
Protein and Daily Calories
Protein contributes 4 calories per gram. If you want to understand how protein fits into your full diet, combine protein grams with calorie needs.
Example:
100 g protein x 4 = 400 calories from protein
The Bottom Line
To calculate protein intake, multiply body weight in kilograms by a daily grams-per-kilogram target. The adult RDA is 0.8 g/kg/day, while active goals are often higher.
Use the Calorie Calculator to see how protein fits into your daily calorie target.
Informational note: Protein needs can vary with age, pregnancy, illness, body composition, and activity. For personalized nutrition advice, ask a qualified clinician or registered dietitian.
How to Calculate: Step-by-Step Guide
Use body weight
Start with your body weight in kilograms, or convert pounds to kilograms first.
Pick a protein target
Choose a daily grams-per-kilogram target based on general needs and activity.
Multiply and distribute
Multiply body weight by the target and spread protein across meals if helpful.