Macro Nutrient Calculator
Calculate daily calories, protein, carbs, and fat from body weight, activity, and goal using Mifflin-St Jeor TDEE. Free, private, and client-side.
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What is Macro Nutrient Calculator?
The Macro Nutrient Calculator is a free browser-based tool that estimates daily calories, protein, carbohydrates, and fat from your body measurements, activity level, and weight goal.
Key Benefits
- Translate TDEE into practical daily macro targets
- Set protein from body weight instead of a fixed percentage
- Compare weight-loss, maintenance, and weight-gain calories
- Keep body measurements private with client-side calculations
Common Use Cases
- •Planning protein and calories for a fat-loss phase
- •Setting maintenance macros after reaching a goal weight
- •Estimating a modest calorie surplus for muscle gain
- •Creating a daily meal plan around gram-based macro targets
How to Calculate Daily Macros
- Enter your measurements: Enter your age, sex used by the Mifflin-St Jeor formula, height in centimeters, and weight in kilograms.
- Choose your activity: Select the activity level that best matches your normal weekly exercise and physical work.
- Choose a goal: Select weight loss for a 20% deficit, maintenance calories, or weight gain for a 10% surplus.
- Review your targets: Calculate and review daily calories plus protein, carbohydrate, and fat grams, then copy the result.
Key Features
- Mifflin-St Jeor BMR and TDEE estimates
- Goal-aware calorie deficit, maintenance, or surplus
- Body-weight-based daily protein target
- Protein, carbohydrate, and fat targets in grams
- Five activity levels with private browser-only calculations
Frequently Asked Questions
How does the macro calculator estimate calories?
It uses the Mifflin-St Jeor equation to estimate basal metabolic rate, multiplies it by your selected activity factor to get TDEE, then applies a 20% deficit for weight loss or a 10% surplus for weight gain.
How are protein, fat, and carbohydrate targets calculated?
Protein is based on body weight and goal: 2.2 grams per kilogram for weight loss and 1.8 grams per kilogram for maintenance or gain. Fat receives 25% of target calories, and carbohydrates receive the remaining calories.
Are macro calculator results exact?
No. BMR and activity factors are population estimates. Use the result as a starting point, track body weight and performance for two to four weeks, and adjust calories with professional guidance when needed.
Does the calculator store my health information?
No. Every calculation runs locally in your browser. Your age, measurements, activity, and goal are not uploaded or stored by this tool.