How to Use the Macro Calculator
Tracking macronutrients—protein, carbohydrates, and fats—is a scientifically proven way to reach specific body composition goals. Whether you want to build muscle, lose body fat, or maintain your current physique, our macro calculator provides the precise breakdown of nutrients your body needs based on your unique biology and activity level.
- Gender, Weight, and Height
- These factors determine your Basal Metabolic Rate (BMR), which is the number of calories your body burns at rest just to keep your organs functioning.
- Activity Level
- This multiplier adjusts your BMR to account for the calories burned during daily movement and exercise (TDEE).
- Fitness Goal
- Selecting "Lose" or "Gain" applies a caloric deficit or surplus to your daily requirements to ensure progress toward your objective.
The Science: How Macros are Calculated
This calculator utilizes the Mifflin-St Jeor Equation, widely considered the most accurate formula for estimating calorie needs. Once your Total Daily Energy Expenditure (TDEE) is established, we split those calories into three main macronutrients:
Protein (4 kcal/g) | Carbohydrates (4 kcal/g) | Fats (9 kcal/g)
- Protein (30%): Essential for muscle repair and satiety. It takes more energy to digest than other macros (thermal effect of food).
- Carbohydrates (40%): Your body's preferred energy source, crucial for high-intensity training and brain function.
- Fats (30%): Necessary for hormone production, nutrient absorption, and long-term health.
Real-World Macro Calculation Example
Scenario: A 30-year-old male, 180cm tall, weighing 85kg, who works out 4 days a week (Moderately Active) and wants to lose weight.
Step-by-Step Calculation:
- BMR: (10 × 85) + (6.25 × 180) – (5 × 30) + 5 = 1,830 kcal
- TDEE: 1,830 × 1.55 (Moderately Active) = 2,836 kcal
- Goal Adjustment: 2,836 – 500 (Deficit) = 2,336 kcal
- Protein: (2,336 × 0.30) / 4 = 175g
- Carbs: (2,336 × 0.40) / 4 = 234g
- Fats: (2,336 × 0.30) / 9 = 78g
Frequently Asked Questions
What if I don't see results after two weeks?
Every body is different. If you aren't losing weight, ensure you are tracking every bite of food accurately. If you still see no change, reduce your carbohydrate or fat intake by another 100-200 calories per day. If you are trying to gain weight and the scale isn't moving, increase your daily intake by 200 calories.
Do I have to hit my macros exactly?
Aim to stay within +/- 5 to 10 grams of your targets. Protein is usually the most important macro to hit for muscle preservation, while carbs and fats can be slightly more flexible as long as your total calorie count remains the same.
Should I adjust my macros on rest days?
While some athletes prefer "carb cycling" (lower carbs on rest days), for most people, consistency is more important. Keeping your macros the same throughout the week makes it easier to stick to a plan and ensures your muscles have fuel to recover on rest days.