Macro Calculator
Get your daily calories and protein, carb, and fat targets based on your body, activity level, and goal. Uses the Mifflin–St Jeor equation.
| Macro | % of calories | Grams/day |
|---|---|---|
| Protein | 30% | 202 g |
| Carbs | 40% | 269 g |
| Fat | 30% | 90 g |
Uses the Mifflin–St Jeor equation and a balanced 30/40/30 split. Estimates only — individual needs vary. Not medical advice.
How to use this calculator
Enter your sex, age, height, and weight, choose your activity level, and pick a goal (lose, maintain, or gain). The calculator returns your daily calorie target plus grams of protein, carbs, and fat.
How macros are calculated
Your BMR (basal metabolic rate) is the energy you burn at rest, estimated with the Mifflin–St Jeor equation. Multiplying by an activity factor gives your TDEE — maintenance calories. To lose weight the calculator targets ~20% below maintenance; to gain, ~15% above. Calories are then split into a balanced 30% protein, 40% carbs, and 30% fat.
Worked example
A 30-year-old man, 5'10", 170 lbs, training moderately and aiming to maintain, lands around 2,600 calories — roughly 195 g protein, 260 g carbs, and 87 g fat per day.
Estimates for general fitness use, not medical or dietary advice. Consult a professional for personalized guidance.
Frequently asked questions
What are macros?
Macros — macronutrients — are protein, carbohydrates, and fat: the three nutrients that supply calories. Protein and carbs have about 4 calories per gram and fat has 9. Hitting target grams of each helps with body composition.
How are my macros calculated?
First the calculator estimates your BMR with the Mifflin–St Jeor equation, multiplies by an activity factor to get your maintenance calories (TDEE), adjusts for your goal, then splits the calories 30% protein, 40% carbs, and 30% fat into grams.
How much protein should I eat?
This tool uses 30% of calories for protein, a solid general target. People who train hard or are cutting often aim higher — around 0.7–1 gram per pound of bodyweight — to preserve muscle.
Should I eat the same macros every day?
Consistency helps, but these are targets to aim for on average. Adjust based on real-world results over a few weeks — if your weight isn't moving as intended, nudge calories up or down by 100–200.