Macro Calculator
Calculate your ideal daily macronutrient targets — protein, fat, carbs, and fiber — tailored to your body, activity level, and weight goal.
| Macro | g / Day | kcal / Day | % of Cals | g / Meal (3×) |
|---|---|---|---|---|
| Enter your details to see results | ||||
* Calculations use the Mifflin-St Jeor equation. For informational purposes only — not medical advice.
Calculate personalized daily targets for protein, fat, carbohydrates, and fiber based on your calorie needs, body weight, and weight goal.
How Macro Calculator Works
Total daily calories start from your Mifflin-St Jeor TDEE, then shift by −500 calories/day for a weight-loss goal or +300 calories/day for a weight-gain goal (0 for maintenance). Protein is set first, at a fixed 0.8g per pound of body weight — a level widely cited as adequate for general health and moderate muscle retention.
Fat is fixed at 25% of your total calorie target and converted to grams by dividing by 9 (the calories per gram of fat). Whatever calories remain after protein and fat are assigned all go to carbohydrates, divided by 4 calories per gram — so your carb target automatically adjusts to fill the rest of your calorie budget.
Fiber is calculated separately from the other three macros, using a general nutritional guideline of 14 grams per 1,000 calories consumed, which scales your fiber target proportionally with your total intake.
See It In Action
Who Uses Macro Calculator and Why
- Turning a calorie target into concrete daily protein, fat, and carb gram goals for meal planning or food tracking apps.
- Making sure protein intake stays adequate while adjusting overall calories up or down for a weight goal.
- Getting a fiber target scaled to your actual calorie intake rather than a generic flat number.
Mistakes to Avoid
- Manually changing the fat percentage without realizing carbs are calculated as whatever's left — since carbs fill the remaining calorie budget here, adjusting fat or protein without checking the resulting carb number can produce an unrealistic target.
- Using the flat 0.8g-per-pound protein figure without considering it's set for general health and moderate muscle retention — someone training heavily for muscle gain may want a higher target than this calculator's default.
- Ignoring the fiber target while focusing only on the three macros — under-eating fiber is a common gap even when calories and macros otherwise look on track.
Tips for Best Results
- If the resulting carb number feels too low or too high for your eating style, that's a sign to manually adjust the fat percentage rather than treating the default 25% as fixed.
- Hit your protein and fiber targets consistently even on days your carb or fat intake varies — those two numbers matter more for how you feel and perform than exact carb precision.
Fixing Common Problems
My carb target looks too low to be practical. — This usually means the fat percentage or overall calorie goal is on the low side for your preferences — try lowering the fat percentage manually to free up more calories for carbohydrates.
Terms Explained
Macronutrients: The three nutrients that supply calories — protein, fat, and carbohydrate — each with a fixed calorie-per-gram value (4, 9, and 4 respectively).