How to use the macro calculator
- Enter your body details and activity level. The calculator first estimates your daily calories (TDEE) with the Mifflin–St Jeor equation.
- Choose a goal: a 500 kcal deficit to lose fat, maintenance, or a small 300 kcal surplus to build muscle with little fat gain.
- Choose a diet style. The calories are split into protein, carbohydrate and fat, shown in grams per day and per meal.
What macros are
Macronutrients are the three nutrients that supply calories:
| Macro | Calories per gram | Main role |
|---|---|---|
| Protein | 4 kcal | Builds and repairs muscle and tissues; keeps you full |
| Carbohydrate | 4 kcal | Main fuel for the brain and for intense exercise |
| Fat | 9 kcal | Hormones, vitamin absorption (A, D, E, K), long-lasting energy |
Alcohol also has calories (7 kcal per gram) but is not a nutrient you need.
Which split should I choose?
- Balanced (30% protein, 40% carbs, 30% fat): a good default for most people and close to general dietary guidelines.
- High protein (40/35/25): helps keep muscle and control hunger while losing fat.
- Lower carb (35/25/40): for people who feel better with fewer carbs or who are less active.
- Keto (25/5/70): very low carb, usually under 50 g a day. It is restrictive; talk to a doctor first if you take medication for diabetes or blood pressure.
For fat loss, the total calories matter more than the exact split. Pick the style you can follow for months, not days.
Example
A 30-year-old woman, 170 cm and 72 kg, lightly active, has a TDEE of about 2,020 kcal. To lose fat she eats about 1,520 kcal. With the balanced split that is 114 g protein (456 kcal), 152 g carbs (608 kcal) and 51 g fat (456 kcal), or about 38 g of protein per meal.
How much protein is enough?
The general adult minimum is 0.8 g per kg of body weight a day. People who exercise, are losing weight or are older usually do better with 1.2–1.6 g/kg, and up to about 2.2 g/kg when trying to keep muscle during a diet. Check your number with our protein calculator.
Frequently asked questions
Do I have to hit my macros exactly?
No. Staying within about 10 g of protein and 5–10% of your calories most days is enough to see results.
Is counting macros better than counting calories?
Macros include calories, plus they make sure you get enough protein. If you only track one number, track calories; if you track two, add protein.
Why does the calculator not go below 1,200 or 1,500 kcal?
Diets below about 1,200 kcal (women) or 1,500 kcal (men) are hard to keep nutritious and should be supervised by a professional, so the calculator does not suggest them.
Do you store my data?
No. Everything is calculated in your browser.
Sources: Mifflin MD, St Jeor ST et al., American Journal of Clinical Nutrition, 1990; US Institute of Medicine, Dietary Reference Intakes for Energy and Macronutrients (Acceptable Macronutrient Distribution Ranges), 2005; Jäger R et al., International Society of Sports Nutrition position stand: protein and exercise, 2017.
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Last reviewed: 2026-11-10. These tools give general information, not medical advice. Talk to a doctor about your health. See our medical disclaimer.