Macro calculator
Enter your age, height, weight, activity and goal to get a daily calorie target with grams of protein, carbs and fat.
How the macro calculator works
It estimates the calories you burn at rest with the Mifflin–St Jeor equation, multiplies that by an activity factor, then adds or subtracts calories for your goal and splits the total into protein, fat and carbs.
- Calories at rest, men: 10 × weight in kg + 6.25 × height in cm − 5 × age + 5. Women: the same, − 161 instead of + 5.
- Maintenance calories: calories at rest × your activity factor (table below).
- Goal: lose fat subtracts 500 kcal a day, roughly 0.5 kg (1 lb) a week at first; build muscle adds 300 kcal; maintain adds nothing.
- Floor: the target never goes below 1,500 kcal for men or 1,200 kcal for women without a doctor’s advice.
- Protein: 1.8 g per kg of body weight when losing fat or building muscle, 1.6 g per kg when maintaining.
- Fat: 25% of calories. Carbs: whatever calories remain.
| Activity level | Factor |
|---|---|
| Mostly sitting, little exercise | 1.2 |
| Light exercise, 1–3 days a week | 1.375 |
| Moderate exercise, 3–5 days a week | 1.55 |
| Hard exercise, 6–7 days a week | 1.725 |
| Hard exercise and a physical job | 1.9 |
Worked examples
| Person | Goal | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| Man, 30, 5 ft 10 in, 180 lb, moderate exercise | Lose fat | 2,260 kcal | 147 g | 276 g | 63 g |
| Woman, 30, 5 ft 5 in, 140 lb, light exercise | Lose fat | 1,360 kcal | 114 g | 141 g | 38 g |
| Man, 25, 6 ft 0 in, 165 lb, moderate exercise | Build muscle | 3,050 kcal | 135 g | 436 g | 85 g |
| Woman, 40, 5 ft 4 in, 160 lb, mostly sitting | Maintain weight | 1,660 kcal | 116 g | 196 g | 46 g |
Get a week of meals built to these numbers
ZivaAI turns a calorie and macro target into a full week of meals with recipes and a grocery list, plus workouts for your equipment.
Coming soon on theApp StoreSources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247.
- Jäger R, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376–384.
These numbers are estimates for healthy adults, not medical advice. If you are pregnant, under 18 or have a health condition, ask a doctor or registered dietitian. Last updated October 28, 2026.