How it works
This calculator estimates your daily calories with the Mifflin-St Jeor equation and an activity factor, adjusts them for your goal, then splits them into protein, carbohydrate and fat.
Splits sit inside the Acceptable Macronutrient Distribution Ranges (protein 10–35%, carbs 45–65% or slightly lower for fat loss, fat 20–35%). Fat loss uses a higher protein share to help preserve muscle in a moderate 500-calorie deficit. Daily calories never drop below 1,200 for women or 1,500 for men.
Protein and carbohydrate provide 4 kcal per gram; fat provides 9. Results are estimates, not medical advice.
Formula
grams = calories × macro % ÷ kcal per gram (protein 4, carbs 4, fat 9)
Questions people ask
What macro ratio is best for losing fat?
Total calories matter most, but a higher protein share (around 25–35% of calories, or 1.6–2.2 g/kg) helps preserve muscle and keeps you fuller during a deficit. The rest can be split between carbs and fat by preference.
Do I need to hit my macros exactly?
No. Being within about 5–10 grams of each target on most days is plenty. Consistency over weeks matters more than precision on any one day.
How many calories are in a gram of each macro?
Protein and carbohydrates each have about 4 calories per gram; fat has about 9. Alcohol has about 7, which this calculator does not include.