Calorie & Macro Calculator
Example: Sex: 1 · Age: 30 years · Weight: 180 lb · Height: 70 in · Activity level: 1.55 · Goal: 0
| Daily calorie target | 2,763 |
| Maintenance calories (TDEE) | 2,763 |
| Protein (g) | 144 |
| Carbs (g) | 374 |
| Fat (g) | 77 |
Worked example
Take a 30-year-old man, 180 lb and 70 in tall, who is moderately active and wants to maintain his weight. Mifflin-St Jeor puts his resting burn at about 1,783 calories, and multiplying by the 1.55 activity factor gives a maintenance level (TDEE) of roughly 2,763 calories a day. With a maintain goal there is no adjustment, so his daily calorie target is also about 2,763. Splitting that out: protein at 0.8g per pound is about 144g, fat at 25% of calories is roughly 77g, and the remaining calories leave about 374g of carbs. Switch the goal to lose weight and the target drops by 500 to about 2,263, with the carbs shrinking to absorb the cut while protein stays put to protect muscle.
Frequently asked questions
Which calorie formula does this use?
It uses the Mifflin-St Jeor equation for resting metabolic rate, which research has found to be more accurate for most people than the older Harris-Benedict formula. That resting number is then multiplied by your activity factor to estimate total daily energy expenditure (TDEE).
Why is protein set per pound of body weight instead of a percentage?
A flat percentage of calories can leave you short on protein when you cut and drowning in it when you bulk. Anchoring protein to 0.8g per pound of body weight keeps intake high enough to preserve or build lean muscle across every goal, which is why this tool sizes it that way rather than as a slice of the calorie pie.
How were the macro percentages chosen?
Protein is set first at 0.8g per pound, fat is set at 25% of your calorie target for hormonal health, and carbohydrates fill whatever calories remain. This keeps protein and fat at sensible floors while letting carbs flex up or down with your goal — the pattern most evidence-based coaches use.
Are these numbers exact?
No calorie formula is exact — Mifflin-St Jeor is an estimate that can be off by 10% or more for any individual, since it cannot see your true muscle mass or metabolism. Use the target as a starting point, then adjust up or down based on how your weight actually moves over two to three weeks.
What activity level should I pick?
Be honest and slightly conservative. Sedentary means a desk job with little exercise; moderately active means training three to five days a week; athlete-level applies to hard daily training or physical jobs. Overestimating activity is the most common reason a calorie target ends up too high.