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Macro Calculator

Get your daily calories, protein, carbs, and fat in 30 seconds — using the same Mifflin-St Jeor math nutrition coaches use with real clients.

How this calculator works

Your basal metabolic rate (BMR) — the calories your body burns at rest — is estimated with the Mifflin-St Jeor equation, the formula with the best track record in validation studies and the one most dietitians default to. We multiply BMR by an activity factor to get your total daily energy expenditure (TDEE), then adjust for your goal: about a 20% deficit for fat loss or a 10% surplus for muscle gain.

Macros are split the way most evidence-based coaches prescribe them:

• Protein — 0.8g per pound of body weight. Protects muscle in a deficit and supports growth in a surplus.
• Fat — 25% of total calories. Enough for hormone health without crowding out carbs.
• Carbs — everything that's left. Fuel for training and recovery.

These are starting points, not laws. Run them for two to three weeks, watch your weight trend (not any single weigh-in), and adjust calories by 5–10% based on real results. That feedback loop is exactly what MacroStack automates — and if you work with a nutrition coach, they can adjust your targets inside the app.

FAQ

Should I eat back exercise calories?
No — your activity multiplier already accounts for training. Eating back exercise calories on top double-counts them, which is one of the most common reasons fat-loss stalls.

How fast should I lose fat on these numbers?
Roughly 0.5–1% of body weight per week. Faster usually means losing muscle; slower is fine and easier to sustain.

What if my weight isn't changing after 3 weeks?
Drop calories ~10% (take it from carbs and fat, keep protein) or add activity. Consistency of logging matters more than perfect targets — most "plateaus" are untracked calories.