How to use the Macro Calculator
- Enter your details and activity level.
- Choose your goal: lose, maintain or gain.
- Press “Calculate” to see grams and calories for each macro.
How macros are calculated
- Calories: your TDEE, minus 500 kcal to lose weight or plus 300 kcal to gain.
- Protein: 1.6 g per kg body weight (2.0 g/kg when losing weight, to help preserve muscle).
- Fat: 25% of calories (at least 0.6 g per kg).
- Carbohydrates: the remaining calories.
- Protein and carbohydrates have 4 kcal per gram; fat has 9 kcal per gram.
Limits of these estimates
Formulas describe averages. Your real needs can differ by 10% or more depending on body composition, genetics, medical conditions and medications. Use the result as a starting point, track your progress for a few weeks and adjust. Pregnant or breastfeeding women, children, and people with medical conditions should ask a doctor or registered dietitian.
Frequently asked questions
Do I need to hit my macros exactly?
No. Staying within about 10% of each target on most days is enough for good results.
Is this suitable for keto?
No. Keto diets use very low carbohydrate targets, which this calculator does not apply.