Macro Calculator

Work out your daily calories and macronutrient targets (protein, carbs, fat) for fat loss, maintenance or muscle gain. Uses Mifflin-St Jeor BMR and TDEE.

Macro Calculator
Advanced macro split
1.6–2.2 g/kg recommended for active adults
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Frequently Asked Questions

Macros (macronutrients) are the three calorie-providing nutrients in your food: protein (4 kcal/g), carbohydrates (4 kcal/g) and fat (9 kcal/g). Tracking macros instead of just calories helps ensure you eat enough protein for muscle and the right balance of energy sources for your goal.

We calculate Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, which is the most accurate for the general population. We then multiply BMR by an activity factor (1.2 sedentary up to 1.9 extremely active) to get Total Daily Energy Expenditure (TDEE). Adjustments are then applied based on your goal: −20% for aggressive fat loss, −10% for moderate cut, 0 for maintenance, +10% for lean bulk, +20% for fast bulk.

Protein is set by bodyweight: ~1.6 g/kg (0.73 g/lb) for general fitness, up to 2.2 g/kg (1.0 g/lb) for cutting on a calorie deficit. Fat defaults to 25–30% of calories for hormonal health. The remaining calories are allocated to carbohydrates. You can override these in the advanced section.

They are good starting estimates based on the most-used scientific equations (Mifflin-St Jeor for BMR, standard activity multipliers). Real-world results depend on individual metabolism, food tracking accuracy, exercise output and adherence. Adjust by ±100–200 kcal/day after 2–3 weeks based on weight trend.

Yes – switch to "Imperial (lb / ft–in)" at the top of the form. Internally we convert to metric for the equations and back for display.

If you have a medical condition (diabetes, heart disease, eating disorder history), are pregnant or breastfeeding, or are under 18, talk to your GP or a registered dietitian before making significant calorie or macro changes. This calculator is for educational purposes only.
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The Equations

Mifflin-St Jeor BMR:

Men: 10×kg + 6.25×cm − 5×age + 5
Women: 10×kg + 6.25×cm − 5×age − 161

TDEE = BMR × activity factor

Macros: protein × g/kg → fat % of cals → carbs from remainder.

Disclaimer

This tool gives estimates for healthy adults using standard equations. It is not medical advice. If you have a medical condition or are under 18, pregnant or breastfeeding, please consult a qualified healthcare professional.