Protein Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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Calories, macros, and nutrient targets can quickly become abstract. Protein Calculator turns the relevant inputs into a practical estimate while keeping the assumptions visible.

What this calculator does

Protein targets are often easier to use when expressed in grams per day. This calculator creates a simple body-weight-based target and shows how many calories and what share of the entered calorie target that protein represents. Nutrition equations are planning tools: real energy and nutrient needs still vary with physiology, goals, health conditions, and the quality of the input data.

How to use it

Enter or select Sex, Height, Current weight, Age, Activity level, Calories, and Show protein intake. Use the units offered by the calculator and keep measurements consistent when you plan to compare results over time.

How the calculation works

The current engine sets protein at 1.6 grams per kilogram of current body weight. It multiplies grams by 4 kcal per gram and divides those protein calories by the entered total calories to show the percentage of energy.

Example

For the sample values prefilled in this calculator, the primary result is 120 g/day (Protein intake), Calories from protein is 480 kcal, and Percent of entered calories is 21.8%. This example is there to show how the inputs flow through the implemented equation; replace the sample values with your own measurements before using the result.

How to interpret the result

The result is a planning target under this fixed 1.6 g/kg rule. It may be useful for general fitness-oriented meal planning, but it is not a universal requirement for every person.

Limitations and notes

Sex, height, age, activity, and the display preference are present in the form but do not change the protein target itself. Kidney disease, pregnancy, older age, energy restriction, and high-level athletic training can require a different protein approach.