Macro Calculator
Calculate your daily calories, protein, carbs, and fat targets based on your body stats, activity level, and goal.
Macro Calculator
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The macro calculator tells you exactly how many grams of protein, carbohydrates, and fat to eat each day to hit your goal — whether that is losing weight, maintaining your current body composition, or building muscle. Macros (macronutrients) are the three nutrients that provide calories: protein (4 cal/g), carbohydrates (4 cal/g), and fat (9 cal/g). Knowing your macro targets is the foundation of evidence-based nutrition. It goes beyond just counting calories by ensuring you eat enough protein to preserve muscle during a cut and enough carbs to fuel performance during training. This calculator uses your BMR (basal metabolic rate) and activity level to find your TDEE (total daily energy expenditure), then adjusts for your goal and splits the result into macro targets. The approach follows the IIFYM (If It Fits Your Macros) method used by competitive athletes and everyday gym-goers alike.
How to Use the Macro Calculator
The Macro Calculator is designed to give you an accurate answer in seconds. Follow these steps:
- Step 1: Select your biological sex (male or female) — the BMR formula uses different constants for each.
- Step 2: Choose metric (kg/cm) or imperial (lbs/inches) and enter your age, weight, and height.
- Step 3: Select your activity level from the dropdown — be honest. Most people are sedentary or lightly active.
- Step 4: Choose your goal: cut (−500 cal/day for ~0.5 kg/week loss), maintain, or bulk (+300 cal/day for gradual muscle gain).
- Step 5: Click Calculate. Your daily calorie target and gram targets for protein, carbs, and fat appear instantly.
No account or sign-up required. All calculations run locally in your browser — nothing is stored or transmitted to any server.
How It Works
BMR (male) = (10 × kg) + (6.25 × cm) − (5 × age) + 5 BMR (female) = (10 × kg) + (6.25 × cm) − (5 × age) − 161 TDEE = BMR × activity multiplier
The calculation runs in two stages: first finding your TDEE, then splitting it into macros. Stage 1 — TDEE: Your BMR is calculated using the Mifflin-St Jeor equation, the most validated formula for predicting resting metabolic rate. BMR is then multiplied by an activity factor (1.2 for sedentary up to 1.9 for athletes) to get your TDEE — the total calories your body burns in a day. Stage 2 — Macro split: Target calories are set at TDEE − 500 (cut), TDEE (maintain), or TDEE + 300 (lean bulk). Protein is set at 1.0g per pound of bodyweight for males (0.85g for females) — the research-supported range for muscle retention and growth. Fat is set at 25% of target calories. Carbohydrates fill the remaining calorie budget. This is a starting point. Adjust your intake based on how your weight trends over 2–3 weeks — real-world metabolism varies by up to 15% from calculated values.
Frequently Asked Questions
How many grams of protein do I need per day?
For most active people, 0.7–1.0g of protein per pound of bodyweight (1.6–2.2g/kg) is the evidence-based range for muscle retention and growth. This calculator uses 1.0g/lb for males and 0.85g/lb for females as a practical default. If you are cutting aggressively, aim for the higher end to preserve muscle.
What is TDEE and why does it matter?
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, accounting for exercise and daily movement. Eating below your TDEE creates a calorie deficit (fat loss); eating above it creates a surplus (weight gain). Your macro targets are built on top of your TDEE, so an accurate activity level selection is critical.
How accurate is the Mifflin-St Jeor formula?
Mifflin-St Jeor is consistently the most accurate BMR formula for the general population in research studies, with a typical error of ±10–15%. It is more accurate than Harris-Benedict. However, no formula accounts for individual variation in metabolic rate — treat the result as a starting point and adjust based on your actual weight trend over 2–3 weeks.
Can I eat the same macros every day?
Daily macro targets work well as weekly averages. Most people find it easier to hit their targets some days and miss slightly on others. As long as your weekly average is close to your targets, results will follow. Tracking apps like MyFitnessPal or Cronometer make daily tracking straightforward.
Is the macro calculator free?
Yes — free with no sign-up required. All calculations run in your browser and no data is stored. Adjust your activity level or goal to see how your macro targets change.