Macro Calculator

Calculate your ideal daily protein, carbs, and fat based on your body composition, activity level, and fitness goal. Protein is calculated from your body weight — not a generic percentage — using the same formulas as our app.

Age

Weight

Height

Activity Level

💻

Sedentary

Office job, no exercise

×1.2

🚶

Lightly Active

Light exercise 1-3 days/week

×1.375

🏃

Moderately Active

Moderate exercise 3-5 days/week

×1.55

🏋

Active

Hard exercise 6-7 days/week

×1.725

⚡

Very Active

Very intense exercise, physical job

×1.9

Your Goal

Lose Fat

Calorie deficit to lose body fat while preserving muscle

Build Muscle

Calorie surplus to support muscle growth

Recomposition

Maintain weight, lose fat and gain muscle simultaneously

Maintain

Stay at your current weight and body composition

Weekly Target

0.25 kg/week

Gentle — easier to maintain

0.5 kg/week

Recommended — sustainable

0.75 kg/week

Aggressive — requires discipline

1.0 kg/week

Maximum — only short term

Body Fat %

Enables Katch-McArdle formula — more accurate for users with higher or lower than average body fat.

Your Results

BMR

—

kcal/day

TDEE

—

kcal/day

Daily Calorie Target
—
kcal/day

Your Daily Macro Targets

—

Protein

—

120g

—

Carbs

—

200g

Ketogenic range — Under 50g net carbs per day puts most people into ketosis. Your body switches from glucose to fat as its primary fuel source.

—

Fat

—

Fills remaining calories after protein and carbs

This Calculator Gives You a Number. The App Makes It Work.

Your macros change every day. The app reads your real calorie burn from Apple Watch, adjusts your deficit as you get closer to your goal, recalculates protein based on this week's workouts, and counts TEF from what you actually ate — not what a formula predicted. Snap a photo of your food and it's tracked.

What Are Macros?

Macronutrients — protein, carbohydrates, and fat — are the three nutrients your body needs in large amounts. Each serves a different function: protein builds and repairs muscle, carbs provide energy, and fat supports hormones and cell function.

Unlike calorie counting alone, tracking macros ensures you are getting the right balance of nutrients — not just the right number of calories. Two diets with the same calories can produce very different results depending on the macro split.

How This Calculator Works

This calculator uses the same formulas as the AI Food Coach app. Your BMR is calculated using Mifflin-St Jeor (or Katch-McArdle if you enter body fat %), multiplied by your activity level for TDEE. Protein is set based on your lean body mass and activity — not a generic percentage. Carbs are scaled by activity level. Fat fills the remaining calories. TEF (Thermic Effect of Food) is included as a bonus.

BMR (Mifflin-St Jeor):
Men: BMR = (10 × W_kg) + (6.25 × H_cm) − (5 × age) + 5
Women: BMR = (10 × W_kg) + (6.25 × H_cm) − (5 × age) − 161

BMR (Katch-McArdle):
LBM = W_kg × (1 − bodyfat/100) BMR = 370 + (21.6 × LBM)

Recommended Macro Splits by Goal

There is no single "best" macro split — it depends on your goal, activity, and body composition. Here are evidence-based starting points:

Goal	Protein	Carbs	Fat	Notes
Lose Fat	1.4–2.0 g/kg	35–45%	25–35%	Higher protein preserves muscle in deficit
Build Muscle	1.6–2.2 g/kg	40–50%	25–30%	Surplus + high protein for muscle synthesis
Recomposition	1.6–2.2 g/kg	35–45%	25–35%	Maintenance calories, high protein
Maintain	1.2–1.6 g/kg	40–50%	25–35%	Balanced for long-term health

Why Protein Is Based on Body Weight, Not Percentages

Most macro calculators set protein as a percentage of calories (e.g., 30%). This is scientifically incorrect. Protein needs are determined by your lean body mass and activity level — not by how many calories you eat. A 60 kg sedentary person and a 100 kg athlete eating the same calories need very different amounts of protein.

This calculator uses 1.2–2.2 g per kg of lean body mass, following ISSN (International Society of Sports Nutrition) guidelines. The exact factor depends on your activity level and whether your goal involves muscle building.

TEF — The Hidden Calorie Bonus

Your body burns calories just to digest food. This is called the Thermic Effect of Food (TEF). Protein costs the most to digest (25% of its calories), followed by carbs (7.5%) and fat (2.5%). A high-protein diet effectively gives you a calorie bonus — you burn more calories without doing anything extra.

Beyond a Static Calculator

This calculator gives you a solid starting point. But in reality, your macro needs change daily — based on your actual activity, what you ate, and how your weight is trending. The AI Food Coach app does this automatically:

Reads your real calorie burn from Apple Watch (not estimates)
Adjusts protein based on your actual workouts this week
Dynamic deficit that adjusts as you approach your goal weight
TEF calculated from what you actually ate today
Keto detection and automatic macro rebalancing

The calculator above uses formulas. The app uses your real data.

Macro Calculator — FAQ

What are macros and why should I track them?

Macros (macronutrients) are protein, carbohydrates, and fat — the three nutrients your body needs in large amounts. Tracking macros instead of just calories ensures you build muscle (enough protein), have energy (enough carbs), and support hormones (enough fat). Two people eating 2000 kcal with different macro splits will get different results.

How many grams of protein do I need per day?

It depends on your body weight and activity level, not on your calorie intake. This calculator uses 1.2–2.2 g per kg of lean body mass (ISSN guidelines). Sedentary: 1.2 g/kg. Moderate exercise: 1.6 g/kg. Heavy training or muscle building: 2.0–2.2 g/kg. If you know your body fat %, the calculation is more accurate because it uses lean body mass instead of total weight.

What is the best macro ratio for weight loss?

There is no single best ratio — it depends on your body and preferences. A good starting point for weight loss: 30-35% protein, 35-40% carbs, 25-30% fat. The key is sufficient protein (to preserve muscle during deficit), moderate carbs (for energy), and adequate fat (for hormones). This calculator sets protein from your body weight, not a percentage, which is more accurate.

What macro split should I use for keto?

Standard keto: 5-10% carbs (20-50g), 20-30% protein, 60-75% fat. Use the Keto preset button in the calculator above to set carbs to 25g. The calculator automatically adjusts fat to fill remaining calories while keeping your protein based on body weight. Below 50g net carbs, you will likely enter ketosis within 2-4 days.

Do macros matter more than calories?

Calories determine whether you lose or gain weight. Macros determine what you lose or gain — muscle or fat. Eating 2000 kcal of mostly protein with moderate carbs and fat will produce a very different body composition than eating 2000 kcal of mostly carbs. For best results, track both: stay within your calorie target AND hit your macro targets.

What is TEF and why is it included?

TEF (Thermic Effect of Food) is the energy your body uses to digest food. Protein costs 25% of its calories to digest, carbs 7.5%, and fat 2.5%. This means a high-protein diet gives you a natural calorie bonus. Most calculators ignore TEF — this one includes it. On a 2000 kcal diet with adequate protein, TEF can be 150-200 kcal/day.

How do I adjust my macros over time?

Recalculate every 2-4 weeks or when your weight changes by more than 2-3 kg. As you lose weight, your BMR decreases and so do your macro targets. If progress stalls, reduce carbs slightly or increase activity rather than cutting calories drastically. The AI Food Coach app does this automatically based on your daily Apple Watch data.

What is body recomposition and how do macros work for it?

Body recomposition means losing fat and gaining muscle at the same time, without changing total weight. It requires eating at maintenance calories with high protein (1.6-2.2 g/kg LBM), moderate carbs, and adequate fat. It works best for beginners, people returning to training, or those with higher body fat. Select "Recomposition" as your goal in the calculator above.