Macro Calculator
Calculate your daily macronutrient targets - protein, carbs, and fat - based on your body stats and goal. This calculator estimates your calorie needs with the Mifflin-St Jeor equation, then splits them into macros using research-backed protein ranges.
How This Calculator Works
Step 1 - Calories. Your basal metabolic rate is estimated with the Mifflin-St Jeor equation (10 x kg + 6.25 x cm - 5 x age, +5 for men or -161 for women), then multiplied by your activity factor to give TDEE. Your goal shifts the target: a 20% deficit for fat loss, maintenance calories to hold weight, and a 10% surplus for muscle gain - rates slow enough to preserve muscle and limit fat gain.
Step 2 - Protein. Protein is set by body weight and goal: 2.2 g/kg for fat loss (higher protein preserves muscle in a deficit, and reviews of lean trainees recommend up to 2.3-3.1 g/kg of fat-free mass), 1.8 g/kg for maintenance, and 2.0 g/kg for muscle gain - all within the 1.6-2.2 g/kg range established by a 2018 meta-analysis in the British Journal of Sports Medicine.
Step 3 - Fat and carbs. Fat is set at 25% of calories, inside the 20-35% acceptable range published by the Institute of Medicine, since fat supports hormone production. Carbohydrates fill the remaining calories - they fuel high-intensity training and are the most flexible part of the split.
References & Sources
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training gains. Br J Sports Med (2018).
- Helms ER, et al. A systematic review of dietary protein during caloric restriction in lean, resistance-trained athletes. J Int Soc Sports Nutr (2014).
- Institute of Medicine. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements - Macronutrient Distribution Ranges.
Frequently Asked Questions
What are the best macros for fat loss?
A moderate calorie deficit (about 20%) with high protein is the evidence-based setup: roughly 2.2 g of protein per kg of body weight, fat at 25% of calories, and the remainder from carbs. The deficit itself drives fat loss - protein's job is to keep the muscle you already built while you lose weight.
What is the best macro ratio for building muscle?
Start with protein at 1.6-2.2 g/kg per day, fat at about 25% of calories, a small 10% calorie surplus, and fill the rest with carbs. Research shows total protein and calories matter far more than the exact ratio, so adjust carbs and fat around your training and food preferences.
How do I calculate my macros by hand?
First estimate calories: 10 x weight(kg) + 6.25 x height(cm) - 5 x age, add 5 for men or subtract 161 for women, then multiply by your activity factor (1.2 sedentary to 1.9 very active). Next set protein grams (weight x 1.6-2.2), take 25% of calories for fat and divide by 9, then give the remaining calories to carbs (4 kcal per gram).
Do macro ratios matter if my calories are on target?
Partly. Getting total calories and protein right explains most of the results. As long as fat stays above the minimum needed for hormones (about 20% of calories), the split between extra carbs and extra fat is flexible - choose the mix that supports your training and keeps you consistent.
TDEE Calculator (Daily Calories)
Calculate your Total Daily Energy Expenditure (TDEE) - the number of calories you burn each day. The calculator uses the Mifflin-St Jeor equation for your basal metabolic rate, multiplied by your activity level.
Protein Intake Calculator
Calculate how much protein you need each day based on your body weight and training goal. This calculator uses the research-backed range of 1.6 to 2.2 grams of protein per kilogram of body weight for building muscle.
1RM Calculator (One-Rep Max)
Estimate your one-rep max (1RM) - the maximum weight you can lift for a single repetition - from a weight you can lift for multiple reps. The calculator uses the Epley and Brzycki equations and averages them.
