Macro Calculator: Daily Calories, Protein, Carbs, and Fat

Macronutrients are the three main categories of food energy: protein, carbohydrates, and fat. Tracking them gives you more control over body composition than tracking calories alone. The same calorie target with different macro distributions can produce very different outcomes for muscle retention, satiety, and energy levels. The starting point for macro targets is your Total Daily Energy Expenditure (TDEE): the total calories your body burns in a day, including exercise. TDEE is calculated from your Basal Metabolic Rate (using the Mifflin-St Jeor equation, the most validated formula for general adult populations) multiplied by an activity factor. From TDEE, this calculator adjusts for your goal: a 500 kcal deficit for weight loss, no change for maintenance, or a 300 kcal surplus for gradual muscle gain. It then divides the target calories into protein, carbs, and fat using ratios that align with standard evidence-based nutrition guidance, with higher protein for weight loss to preserve muscle.

• Setting up a fat-loss diet: Select the lose-weight goal to see a 500 kcal deficit with a higher protein split. High protein during a deficit helps preserve muscle mass while losing fat, which most fat-loss protocols prioritize.
• Building a muscle-gain phase: The gain option adds 300 kcal and uses a balanced macro split. A smaller surplus than the old 500 kcal bulk reduces fat gain while still providing enough energy for muscle protein synthesis.
• Comparing activity level impact on calories: Run the calculator twice with different activity levels to see how much your calorie needs change. Going from sedentary to moderate activity often adds 400-600 kcal to TDEE, which changes how much you need to eat to maintain weight.
• Meal planning and food logging: Use the gram targets to build a daily meal plan. Each meal can target roughly one-third of the daily macro totals. Gram targets are more actionable than percentage targets when reading nutrition labels.

• Overestimating activity level: People often select a higher activity level than their actual lifestyle. Three gym sessions per week is "light" activity if the rest of the day is mostly sitting. Honest selection gives better calorie targets.
• Chasing precise gram targets every day: Macro targets are weekly averages, not daily requirements. Being within 10-15% of daily targets consistently is far more sustainable and effective than obsessing over hitting exact grams every single day.
• Setting too large a calorie deficit: Deficits larger than 500-700 kcal/day accelerate muscle loss and make adherence harder. A 500 kcal deficit produces about 0.5 kg of fat loss per week, which is considered sustainable by most nutrition guidelines.
• Ignoring protein on a surplus: Even on a calorie surplus for muscle gain, inadequate protein limits muscle protein synthesis. The 30% protein split in this calculator is a baseline. Strength athletes often benefit from 35-40% protein during a gaining phase.

1. 1Enter your weight, height, age, and sex. These feed into the Mifflin-St Jeor BMR formula.
2. 2Select your activity level. This multiplies BMR by a factor from 1.2 (desk-bound, no exercise) to 1.9 (physically demanding job plus daily training).
3. 3Select your goal: lose weight (deficit of 500 kcal), maintain, or gain muscle (surplus of 300 kcal).
4. 4The calculator applies the macro split: 35/35/30 (protein/carbs/fat) for weight loss, 30/40/30 for maintenance and gain.
5. 5Each macro's calorie allocation is converted to grams (protein and carbs: calories / 4; fat: calories / 9).
6. 6Results show both grams and calories for each macronutrient, plus your BMR and TDEE for reference.

• Adjust based on real results after 2-3 weeks: TDEE formulas are population estimates. If you are eating at your calculated maintenance and consistently gaining or losing weight, adjust calories by 100-200 kcal in the appropriate direction until weight stabilizes.
• Prioritize hitting protein first: If you can only track one macro, track protein. Adequate protein preserves muscle during a deficit and supports recovery during a surplus. Carbs and fat can flex more without dramatically affecting body composition outcomes.
• Use a food scale for the first month: Most people significantly under- or over-estimate portion sizes by eye. Weighing food for 4-6 weeks builds accurate calibration that you can eventually maintain without a scale.
• Recalculate when weight changes by 5 kg: As body weight changes, so does BMR and TDEE. A person who has lost 10 kg has a lower maintenance calorie level than when they started. Update the calculator every time you reach a new 5 kg milestone.