IIFYM Custom Macro Calculator
If It Fits Your Macros. Stop restricting food groups and start tracking gram targets for sustainable fat loss.
IIFYM Custom Macro Calculator Methodology & Instructions
Step-By-Step Guide
- Enter your daily calorie target (from our TDEE tool).
- Enter your body weight (essential for protein baseline).
- Select your diet preference (Balanced, Low Carb, High Carb).
- Click calculate to generate you precise breakdown of Protein, Fat, and Carbs.
Macronutrient Algorithm
Carbs = (Total Calories - ProteinCal - FatCal) / 4
Understanding Your Results
| Macronutrient | Calories per Gram | Primary Purpose for Dieting |
|---|---|---|
| Protein | 4 kcal | Maintains skeletal muscle tissue during cuts. High thermic effect (burns calories to digest). |
| Dietary Fat | 9 kcal | Essential for hormonal regulation, testosterone production, and vitamin absorption. Never drop below 20%. |
| Carbohydrates | 4 kcal | Primary energy source (glycogen) to fuel intense gym sessions. Used to fill the remainder of caloric diets. |
Frequently Asked Questions
What is IIFYM?
IIFYM stands for If It Fits Your Macros. It is a flexible dieting approach that focuses on hitting daily gram targets for Protein, Carbohydrates, and Fats, rather than restricting specific food types.
Why do macros matter for fat loss?
While calories determine weight loss, macros determine what kind of weight you lose. Sufficient protein combined with training ensures you lose fat rather than muscle.
Primary Reference Sources: Journal of the International Society of Sports Nutrition (Flexible Dieting)
Standardized Calculation Engine · Last updated July 6, 2026