How the calculation works
Each macro gets a share of your daily calories. That share is turned into grams with the standard energy values (Atwater factors) that the GreaseFit app also uses: protein and carbohydrates provide 4 kcal per gram, fat provides 9 kcal per gram.
If you let the calculator work out your calories, it uses your maintenance calories (TDEE) from the Mifflin-St Jeor equation, with the same activity multipliers as the calorie calculator and the app.
The formula
- Protein:
grams = calories × protein % ÷ 4 - Carbohydrates:
grams = calories × carbs % ÷ 4 - Fat:
grams = calories × fat % ÷ 9
The presets
These are the same splits you can choose in the GreaseFit app, as a percentage of daily calories.
| Preset | Protein | Carbohydrates | Fat |
|---|---|---|---|
| Balanced | 30% | 40% | 30% |
| High protein | 40% | 30% | 30% |
| Low carb | 35% | 20% | 45% |
| Keto | 30% | 5% | 65% |
With Custom you set the three percentages yourself. They must add up to 100%.
Example: at 2,000 kcal a day on the Balanced split, protein is 2,000 × 30% ÷ 4 = 150 g, carbohydrates 2,000 × 40% ÷ 4 = 200 g and fat 2,000 × 30% ÷ 9 = 66 g (66.7, rounded down).
Which split should I choose?
- Balanced suits most people and is a sensible place to start if you have no strong preference.
- High protein helps if you train for strength or want to stay full while eating less. Check the gram figure against the protein calculator.
- Low carb moves energy from carbohydrates to fat, for people who feel better eating fewer starches and sugars.
- Keto keeps carbohydrates very low (5%). It is a restrictive diet: talk to a doctor first if you have diabetes, take medication or have a medical condition.
- The best split is the one you can stick to. Total calories matter most for weight change; the split mainly affects how full you feel and how you perform.
Related calculators
- Calorie calculator: estimate your maintenance calories and a starting point to lose or gain weight.
- Protein calculator: find a daily protein target from your body weight and goal.
Limitations
- The split is a target, not a prescription. Day-to-day variation is normal, so look at your average over a week.
- Percentages scale with calories, so at a low calorie intake a percentage split can leave you short on protein. Check your protein in grams per kilogram as well.
- Food labels round their values, so logged totals will not match the formula to the gram.
- It is not designed for people under 18, for pregnancy or breastfeeding, or for medical diets.
