Macro Calculator – Daily Protein, Carbs & Fat Targets

Macro Calculator

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Calculate My Macros

Estimates only — based on the Mifflin-St Jeor equation. For medical or athletic nutrition advice, consult a qualified professional.

About Macro Calculator

Hit Your Daily Protein, Carbs and Fat Targets

Calories tell you how much to eat, but macros tell you what to eat — and that distinction is what separates people who spin their wheels from people who actually transform their bodies. Whether your goal is fat loss, muscle gain or simply eating smarter, our free Macro Calculator turns your age, size and activity level into precise daily targets for protein, carbohydrates and fat.

The approach is called IIFYM — "If It Fits Your Macros." Instead of banning foods, you get a daily budget of each macronutrient and the freedom to spend it however you like. Research consistently shows that flexible, macro-based dieting beats rigid meal plans for long-term adherence, because nothing is off-limits — it just has to fit. This calculator builds your personal macro budget using established sports-nutrition science, starting from your metabolic rate and adjusting for your goal.

No sign-up, no app download, no subscription. Enter six details about yourself and get your BMR, TDEE, calorie target and gram targets for all three macros — with a visual breakdown you can screenshot and stick on the fridge.

What Are Macros, Exactly?

Macronutrients are the three nutrient groups that supply essentially all your food energy:

• Protein (4 kcal per gram): Builds and repairs muscle, keeps you full, and has the highest thermic effect — your body burns roughly 20–30% of protein calories just digesting it. Sources: meat, fish, eggs, dairy, legumes, tofu.
• Carbohydrates (4 kcal per gram): Your body's preferred fuel, especially for the brain and high-intensity training. Sources: rice, oats, potatoes, fruit, bread.
• Fat (9 kcal per gram): Essential for hormones, vitamin absorption and brain health. Sources: olive oil, nuts, avocado, fatty fish.

Alcohol is technically a fourth energy source (7 kcal/g), but it provides no nutritional value and is not part of macro targets. The calculator splits your calories across protein, carbs and fat in ratios matched to your goal.

Step 1: Your BMR (Mifflin-St Jeor Equation)

Everything starts with your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest just keeping you alive. The calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate formula for the general population:

• Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
• Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

For example, a 30-year-old man weighing 80 kg at 180 cm: (10 × 80) + (6.25 × 180) − (5 × 30) + 5 = 800 + 1125 − 150 + 5 = 1,780 kcal/day at rest. Want to explore your metabolic numbers further? Our BMR calculator dives deeper into basal metabolic rate alone.

Step 2: Your TDEE (Activity Multipliers)

BMR is only the baseline — you also burn calories moving, working and exercising. Multiplying BMR by an activity factor gives your TDEE (Total Daily Energy Expenditure):

• Sedentary (desk job, little exercise): × 1.2
• Lightly active (light exercise 1–3 days/week): × 1.375
• Moderately active (moderate exercise 3–5 days/week): × 1.55
• Very active (hard exercise 6–7 days/week): × 1.725
• Extra active (physical job + hard training): × 1.9

Our example man, moderately active: 1,780 × 1.55 = 2,759 kcal/day TDEE. Be honest here — most people overestimate their activity. When in doubt, pick the lower tier; you can always adjust after two weeks of tracking your weight trend.

Step 3: Adjusting for Your Goal

• Cutting (fat loss): subtract 15–20% from TDEE. Our example: 2,759 × 0.8 ≈ 2,207 kcal/day. This yields roughly 0.5% of body weight lost per week — the sweet spot for keeping muscle.
• Maintaining: eat at TDEE (2,759 kcal). Ideal for holding your physique or recomposition phases.
• Bulking (muscle gain): add 10–15% to TDEE ≈ 3,035–3,173 kcal/day. A modest surplus builds muscle while limiting fat gain.

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Step 4: Setting Your Macro Targets

With the calorie target set, the calculator assigns protein and fat first (they have physiological minimums), then fills the rest with carbs:

• Protein: 1.6–2.2 g per kg of body weight (up to 2.4 g/kg when cutting aggressively). Our 80 kg example cutting at 2.0 g/kg = 160 g protein (640 kcal).
• Fat: 0.8–1.0 g per kg for hormone health. At 0.9 g/kg = 72 g fat (648 kcal).
• Carbs: whatever calories remain. 2,207 − 640 − 648 = 919 kcal ÷ 4 = ~230 g carbs.

Final targets: 160g protein / 230g carbs / 72g fat. The calculator shows this as grams plus a visual bar, and recalculates instantly if you change any input. For a fuller picture of your body composition goals, check your numbers against our body fat calculator.

How to Use the Macro Calculator

1. Enter your age, sex, height and weight.
2. Select your activity level honestly.
3. Choose your goal: cut, maintain or bulk.
4. Click Calculate — instantly see BMR, TDEE, calorie target and all three macro targets in grams.
5. Screenshot or note your targets, then track food with any nutrition app for 2–3 weeks before adjusting.

Making Your Macros Work in Real Life

Numbers only work if you follow them, so keep it practical: prioritize protein at every meal (a palm-sized portion of meat, fish or legumes), do not fear carbs around workouts — they fuel performance and recovery — and keep fats mostly unsaturated (olive oil, nuts, fish) rather than fried and processed. Weigh food for the first two weeks; most people are shocked at what a "tablespoon" of peanut butter actually looks like. Re-run the calculator every 4–6 weeks or after every 3–5 kg of weight change, because a lighter body burns fewer calories. And remember sleep matters enormously for fat loss — poor sleep raises hunger hormones, so plan your rest with our sleep cycle calculator too.

Frequently Asked Questions

How accurate is the Mifflin-St Jeor equation?

It is the most validated BMR formula for the general population, typically within ±10% of lab-measured values. Very muscular or very lean individuals may find it slightly underestimates; in that case, track and adjust based on real weight trends over 2–3 weeks.

Should I eat back exercise calories?

No — your activity level selection already includes exercise. "Eating back" calories from a fitness tracker usually double-counts and stalls fat loss. Pick the right activity tier once and trust it.

Can I lose fat and build muscle at the same time?

Beginners, detrained lifters and those with higher body fat often can ("recomposition") by eating near maintenance with high protein (2.0–2.4 g/kg). For most others, dedicated cut and bulk phases work better. Our ideal weight calculator can help you set a realistic target weight for each phase.

Do I need to hit my macros exactly every day?

Hit protein and calories within about 5–10% daily; carbs and fat can flex as long as calories land on target. Weekly averages matter more than any single day — one off day does not ruin progress.

Is this medical advice?

No. This calculator is an educational planning tool. If you have diabetes, thyroid issues, an eating disorder history or any medical condition, consult a doctor or registered dietitian before changing your diet.

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