Macro Calculator
Split your daily calories into grams of protein, carbohydrate and fat within the recommended ranges.
Protein a day
108 grams
- Carbohydrate
- 269 g
- Fat
- 72 g
- Daily calories
- 2,151 kcal
- Carbohydrate share
- 50%
At about 2,151 calories a day, a split of 20% protein, 50% carbohydrate and 30% fat is about 108 g of protein, 269 g of carbohydrate and 72 g of fat.
Calculation breakdown
| Step | Formula | Result |
|---|---|---|
| Daily calories | Mifflin-St Jeor resting energy × activity level (midpoint) | 2,151 kcal |
| Protein | 2,151 × 20% ÷ 4 kcal per gram | 108 g |
| Fat | 2,151 × 30% ÷ 9 kcal per gram | 72 g |
| Carbohydrate | 2,151 × 50% ÷ 4 kcal per gram | 269 g |
How it works
Enter your details as in the calorie calculator, then choose the share of calories that comes from protein and from fat. Carbohydrate is the remainder.
Worked example
A day of 2,000 calories with 20% protein and 30% fat:
- Carbohydrate share: 100 − 20 − 30 = 50%
- Protein: 2,000 × 20% ÷ 4 = 100 g
- Carbohydrate: 2,000 × 50% ÷ 4 = 250 g
- Fat: 2,000 × 30% ÷ 9 = 66.7 g
Rounding
Grams are shown to the nearest whole gram. The calculations use the unrounded values.
Sources
Frequently asked questions
How do you calculate macros?
Start with your daily calorie estimate, choose the share of calories for protein and fat, and give the rest to carbohydrate. Then divide each share by the calories per gram, which are 4 for protein, 4 for carbohydrate and 9 for fat. At 2,000 calories, 20% protein is 100 g, 30% fat is about 67 g and 50% carbohydrate is 250 g.
What are the recommended macro ranges?
The Dietary Guidelines for Americans list acceptable ranges for adults of 10% to 35% of calories from protein, 45% to 65% from carbohydrate and 20% to 35% from fat. These ranges were set by the National Academies. The calculator only accepts splits that fall inside them.
Where do the daily calories come from?
They come from the calorie calculator on this site, which uses the Mifflin-St Jeor equation for resting energy and the middle of the activity range from the FAO, WHO and UNU report. It estimates the calories your body uses, not a target for gaining or losing weight.
Does this calculator set a calorie goal for weight loss or gain?
No. It splits the calories your body is estimated to use. If you want to change your weight, talk to a doctor or registered dietitian about a safe target. The calculator deliberately offers no deficit or surplus settings.
Why are calories per gram 4, 4 and 9?
These are the general Atwater factors, which food labels commonly use. Protein and carbohydrate provide about 4 kilocalories a gram and fat about 9. Real foods vary slightly, so the figures are estimates.
Results are estimates for information only, not medical or dietary advice. Ask a doctor or registered dietitian about your own needs.