How to Use This Calculator
Enter body weight in kg or lbs, then pick your activity level (Sedentary, Active or Athlete), your goal (Maintain, Build muscle or Fat loss) and how many meals you eat a day (3, 4 or 5). Click Calculate to see your daily target in grams, the amount per meal and the weekly total.
Why Goal Changes the Target, Not Just Body Weight
Protein needs change with what you are trying to do. In a calorie deficit, a higher intake helps hold on to lean mass, and harder training needs more protein for recovery. That is why this calculator uses a different g/kg factor for each goal and activity level instead of one flat rule like 1 g per pound.
Protein per Meal for the 80 kg Example
The table follows the 80 kg example on this page: 144 g of protein per day. The daily total stays the same, and only the split changes with the number of meals you pick in the calculator.
| Meals per day | Protein per meal | Daily total | Weekly total |
|---|---|---|---|
| 3 meals | 48 g | 144 g | 1,008 g |
| 4 meals | 36 g | 144 g | 1,008 g |
| 5 meals | 28.8 g | 144 g | 1,008 g |
The per-meal figure is the daily grams divided by the meals, so more meals means a smaller amount at each one. This holds for any goal, including a protein intake calculator for weight loss or for muscle gain.
Pounds to Kilograms Before You Multiply
The calculator converts pounds to kg first (1 lb is 0.4536 kg), because the g/kg factors work on kilograms. If you do it by hand, convert first and then multiply by the factor.
| Weight in lbs | Weight in kg |
|---|---|
| 150 lb | 68.0 kg |
| 175 lb | 79.4 kg |
| 200 lb | 90.7 kg |
Using the Calculator on Tirzepatide or Other GLP-1 Medicines
This works as a tirzepatide protein intake calculator or a GLP-1 protein intake calculator in the maths sense only. Enter your body weight, choose the fat loss goal and your activity level, and it returns grams per day and per meal. It does not change its factors for any medicine, and it gives no medical advice. If your portions are smaller, the table above shows how the same daily total splits across more meals. For a target that fits your own situation, ask your prescriber or a dietitian. To work out a syringe draw for the medicine itself, use the tirzepatide calculator.
Tracking Alongside Body Composition
Protein intake is most useful as a number tracked alongside actual body composition change. The Body Fat Percentage Calculator gives a consistent way to measure that change over the same period, and the Creatine Loading Calculator covers the other supplement variable commonly tracked during a body-recomposition phase.
Who Should Use This
Researchers and athletes monitoring dietary protein; nutrition researchers needing reference intake ranges.
What This Calculator Does
The Protein Intake Calculator provides weight-based daily protein targets derived from sports nutrition research, covering maintenance, muscle gain, fat loss, and high-performance ranges.
Formula Used
These factors sit within the ISSN guidance of 1.4 to 2.0 g/kg per day for active people, with higher intakes supported during fat loss. The 2.3 to 3.1 g figure often quoted for dieting athletes is per kg of lean body mass, not total body weight (Helms et al., 2014).
Example Calculation
Limitations
Reference ranges are population averages from sports nutrition literature. Individuals with kidney disease, specific metabolic conditions, or unusual body composition may require different targets. Consult a dietitian for personalised guidance.
Frequently Asked Questions
How much protein do I need per day to build muscle?
Research consistently supports 1.6-2.2 g of protein per kg of body weight per day (0.73-1 g per lb) for maximizing muscle protein synthesis in resistance-trained individuals. The Protein Intake Calculator factors in your weight, activity level, and goal to generate a personalized daily target.
Does protein timing matter for muscle growth?
Total daily protein intake matters most. However, distributing protein across 3-5 meals of 25-40 g each optimizes muscle protein synthesis throughout the day. Consuming protein within 2 hours of resistance training provides an additional but modest benefit for muscle building.
What are the best protein sources for muscle building?
Complete protein sources containing all essential amino acids are optimal: eggs, chicken, beef, fish, dairy products (whey and casein), and soy. Whey protein contains the highest leucine content and is rapidly absorbed, making it particularly effective immediately after training.
Can eating too much protein be harmful?
For healthy adults with normal kidney function, current research does not support a harmful upper intake level for protein. Studies of intakes up to 3.3 g/kg/day in healthy resistance-trained individuals show no adverse effects on kidney or liver function. Excess protein is oxidized for energy rather than stored as fat directly.
How do I calculate my daily protein intake?
Convert your weight to kg (divide lbs by 2.205), then multiply by the g/kg factor for your goal and activity level. For example, 80 kg x 1.8 is 144 g of protein per day. Divide that by the number of meals to get the grams per meal: 144 / 4 is 36 g. Enter your weight, activity level, goal and meals in the calculator and it does the steps for you.
How do I use this protein intake calculator on tirzepatide or another GLP-1 medicine?
Enter your body weight, choose the fat loss goal and your activity level, then pick the number of meals. The calculator gives grams per day and per meal using the same weight x factor maths for everyone. It does not adjust for any medicine and it is not medical advice. If you eat fewer or smaller meals, a different meal count shows how the same daily total splits. Ask your prescriber or a dietitian for a target that fits you.