Macronutrients — "macros" — are the three nutrients providing all dietary calories: Protein (4 kcal/g) builds muscle and is the most satiating macro. Carbohydrates (4 kcal/g) are the primary fuel for high-intensity exercise. Fat (9 kcal/g) supports hormone production and fat-soluble vitamin absorption.
Calories determine weight change. Macros determine whether that change is fat or muscle. Hit protein first — every single day.
How to use your macro targets
1. Protein first, always
Hit your protein target every day regardless of carbs and fat — use the protein calculator for goal-specific targets. If you can only track one number, track protein. Carbs and fat are flexible — protein is not.
2. Use a food tracking app with a kitchen scale
Apps like Cronometer or MyFitnessPal let you scan barcodes and log accurately. Use a kitchen scale for the first 2–3 weeks — most people are surprised how far off their visual estimates are.
3. Adjust after two weeks
If weight is not moving as expected after 14 days of consistent tracking, adjust total calories by 100–150 kcal. Keep protein fixed and adjust carbs and fat proportionally.
The 80% rule: Hitting within 10–15% of your targets consistently each week produces essentially the same results as perfect daily accuracy.
Frequently asked questions
What are macros and why do they matter?
Macros are protein, carbohydrates, and fat — the three nutrients providing all calories. Total calorie intake determines weight change; macro distribution determines whether that change is fat or muscle.
How much protein do I need per day?
For active individuals, 1.6–2.2g/kg bodyweight is supported by research. This calculator uses 0.85g/lb as a practical middle ground. Sedentary adults need approximately 0.8g/kg for basic health.
Should I track macros or just calories?
Calories control weight change. Macros control body composition — especially important when minimising muscle loss on a cut or maximising lean gains on a bulk. At minimum, track protein and let carbs and fat be flexible.
Do I need to hit my macros exactly every day?
No. Being within 10–15% of targets consistently across a week produces essentially the same outcome as hitting exact numbers daily. Weekly averages matter more than daily precision.