Macro Calculator
Personal details
Enter height, weight, and lifestyle. We estimate maintenance calories, then split your daily target into protein, carbs, and fats.
Results
| BMR (resting metabolism) | — |
|---|---|
| Calories to maintain weight | — |
| Your daily calorie target | — |
| Protein | — |
| Carbohydrates | — |
| Fat | — |
Week-by-week calorie plan
As your weight moves toward the target, maintenance calories change. Each week shows updated maintenance and the same daily surplus or deficit you selected.
| Week | Est. weight | Maintenance (kcal) | Target intake (kcal) |
|---|
How to Use This Macro Calculator
Meal plans on social media rarely match your desk job, your training block, or the weight you actually want to hit six months from now. This tool follows the same workflow as a full macronutrient calculator: you supply height, weight, age, and activity, pick a goal, and receive maintenance calories plus gram targets for protein, carbohydrates, and fats.
- Enter personal details. Choose sex, age, height, and current weight. Metric and imperial units are both supported—the math always converts to kilograms and centimeters for the Mifflin–St Jeor equation.
- Select activity level. Pick the description closest to your typical week, from sedentary office work through daily hard training or a physical job.
- Set your goal. Maintain weight uses maintenance calories only. For loss or gain, enter a target weight and a moderate (±500 kcal/day) or strict (±1000 kcal/day) pace.
- Choose a macro split. Presets mirror common ranges (for example 20% protein, 60% carbs, 20% fat). Advanced users can enter custom percentages that sum to 100%.
- Press Calculate. Review BMR, maintenance calories, your daily target, macro grams, and—when dieting—a week-by-week intake table that adjusts as weight changes.
For total daily energy without macro splits, use the Calorie Calculator or BMR Calculator. To estimate exercise burn separately, try the Calories Burned Calculator.
Macro Calculator Formulas and Practical Applications
Maintenance calories start with basal metabolic rate (BMR)—energy at complete rest—then scale by activity. Macro grams come from calorie percentages and standard energy density.
Mifflin–St Jeor BMR
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Multiply BMR by an activity factor to estimate calories to maintain weight. Sedentary lifestyles often use 1.2; light through athlete tiers use factors up to 2.3 for professional training loads.
Weight change and macro grams
Many planners assume roughly 3,500 kcal per pound of body-weight change, so a 500 kcal/day deficit targets about one pound per week. Protein and carbohydrates each provide about 4 kcal/g; fat provides about 9 kcal/g. Gram targets = (calorie target × percent) ÷ kcal per gram.
Dietary references often suggest protein around 10%–35% of calories, carbohydrates 45%–65%, and fats 20%–35%, with a practical floor near 0.8 g protein per kg body weight for many adults. Presets sit inside those bands; they are starting points, not prescriptions for medical diets.
IIFYM and meal planning
“If It Fits Your Macros” (IIFYM) tracks protein, carbs, and fats instead of banning specific foods. The flexibility helps adherence, but it does not replace micronutrient quality, fiber, or clinical guidance for diabetes, kidney disease, pregnancy, or eating disorders. Use macro targets to structure plates—lean protein, produce, whole grains, and unsaturated fats—rather than to justify empty calories every day.
Frequently Asked Questions
What are macronutrients?
Protein builds and repairs tissue; carbohydrates fuel training and brain work; fats support hormones and carry fat-soluble vitamins. All three contribute to daily energy when you track “macros.”
What is basal metabolic rate (BMR)?
BMR is resting energy expenditure—breathing, circulation, cell repair—before deliberate exercise. It is lower than total daily burn unless you choose a sedentary maintenance estimate.
How many calories should I eat to lose one pound per week?
A daily deficit near 500 kcal is a common starting point for roughly one pound per week. Heavier deficits speed the scale but increase fatigue and muscle-loss risk; the calculator flags targets below BMR.
What macro split should I use?
Endurance athletes often tolerate higher carbohydrate presets; strength-focused plans may bump protein. Start with a preset, log intake for two weeks, then adjust based on energy, hunger, and performance—not only the scale.
Is it safe to eat below my BMR?
Long-term intake under estimated BMR is discouraged for most adults without supervision. Aggressive 1,000 kcal/day deficits can push targets there quickly—treat strict pace as a short-term option only with professional support.