Macro for Men Calculator

The Macro for Men Calculator estimates how many calories you need each day and breaks them into a practical protein, carbohydrate, and fat plan. It uses the Mifflin-St Jeor equation to estimate resting energy needs, then applies an activity multiplier and your chosen goal, whether you want to lose fat, maintain weight, or build muscle.

Enter your age, height, weight, typical activity level, and goal. If you know your body fat percentage, add it for a more personalized lean-mass calculation. The results include maintenance calories, goal calories, exact macro grams, a calorie split, and a step-by-step breakdown, so you can start planning meals with confidence.

💪 Enter Your Details

⚙️ Lifestyle & Goals

%
Enter body fat to switch from Mifflin-St Jeor to the Katch-McArdle lean-mass formula.
Quick goals:
Maintenancekcal/day
Goal Calorieskcal/day
Proteingrams
Carbsgrams
Fatgrams
⚡ Calorie split:

How to Use This Tool

Fill in your age, height, weight, activity level, and goal, then press Calculate Macros. The tool works in either metric or imperial units — just choose cm/in and kg/lb before calculating. If you know your body fat percentage, add it to switch the energy estimate to a lean body mass formula, which is often more accurate for trained or very lean men.

Tip: Be honest about your activity level. A desk job plus three gym sessions is usually lightly active, not moderately active. Overestimating activity is one of the most common reasons macro targets feel too generous.

How It Works

Your daily energy needs are built from two steps: an estimate of resting metabolic rate (BMR), then a multiplier for activity. This calculator uses the widely cited Mifflin-St Jeor equation by default.

Mifflin-St Jeor for men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. Your maintenance calories are then BMR × activity factor.

When body fat is provided, the tool switches to the Katch-McArdle formula: BMR = 370 + 21.6 × lean body mass (kg). Lean mass is calculated as total weight minus fat mass, so this method rewards accurate body-fat measurements. The final calories are adjusted by your goal: a 20% deficit for fat loss, no change for maintenance, or a 15% surplus for muscle building.

Worked Example

A 38-year-old man, 180 cm, 85 kg, moderate activity, wants to build muscle. His BMR is 10×85 + 6.25×180 − 5×38 + 5 = 1,770 kcal. With a 1.55 activity factor, maintenance is about 2,744 kcal, and a 15% surplus gives about 3,155 kcal. At 1.8 g/kg he needs 153 g protein; fat at 20% of calories is about 70 g, and the remaining carbs work out to roughly 360 g per day.

Macro Split Reference

These are common starting splits used by coaches and nutrition apps. You can adjust the fat and protein targets to suit your preferences and training style.

GoalProteinCarbsFat
Lose fat30%40%30%
Maintain weight30%40%30%
Build muscle25%50%25%

Tips & Best Practices

  • Weigh yourself 3–4 times per week and use a weekly average before adjusting calories.
  • Re-check your macros every 5–7 kg of weight change, since your energy needs move with body weight.
  • Prioritize protein at every meal to support appetite control and muscle retention.
  • Treat the calorie target as a starting point. After two weeks, adjust by 5–10% if progress is too fast or too slow.
  • Whole foods should make up most of your diet, but flexible eating means no single meal "ruins" your plan.

Frequently Asked Questions

Are these macros exact? No calculator can be perfect. Energy needs vary with genetics, hormones, sleep, and daily movement. Use the results as a well-informed starting point and track real-world progress.

Is the Katch-McArdle formula better? It can be more accurate than Mifflin-St Jeor if you know your body fat percentage and it is measured reliably. If your body-fat estimate is inaccurate, the formula simply inherits that error.

Should I count macros forever? Most people benefit from tracking for a few weeks to learn portion sizes, then transition to loose habits. Tracking short-term builds awareness.

The Mifflin-St Jeor equation is explained in detail on Wikipedia, and general dietary guidance is available from the Dietary Guidelines for Americans. For a simpler approach that also works for women, try the general macro calculator.