On this page
Formula
grams = daily calories × share of calories ÷ kcal per gram (protein 4, carbohydrates 4, fat 9)
- daily calories
- your calorie target in kcal, after any adjustment you choose
- share of calories
- the percentage of calories from that macronutrient, as a decimal (30% → 0.30)
- kcal per gram
- the Atwater energy factor — 4 kcal for protein and carbohydrates, 9 kcal for fat
What the macro calculator does
Macronutrients, or “macros”, are the three nutrients that supply calories: protein, carbohydrates and fat. This macro calculator takes a daily calorie target and splits it into grams of each, which is the number you track on food labels and in nutrition apps.
You get:
- Grams of protein, carbohydrates and fat per day, the main result.
- Calories from each macro and its share of the total.
- A comparison with the adult AMDR, the ranges set by the Institute of Medicine for a nutritionally adequate diet.
- Protein per kilogram and per pound of body weight, if you add your weight.
The calculator does not guess your calorie needs. Enter a target you already have, or estimate your maintenance calories with the TDEE calculator and use the adjustment to subtract or add calories.
How to use the macro calculator
- Enter your daily calories. Use either your target, or your maintenance calories plus an adjustment.
- Pick an adjustment. Choose “None” if the number is already your target. Otherwise subtract 250 or 500 kcal for weight loss, or add 250 or 500 kcal for weight gain.
- Choose a macro split. Balanced, high protein, low carb, or custom percentages.
- For a custom split, fill in all three percentages so they add up to 100.
- Optionally add your weight to see protein relative to body size.
How to calculate macros by hand
Every macro target follows the same two steps: calories × percentage, then ÷ calories per gram. Protein and carbohydrates provide 4 kcal per gram and fat provides 9 kcal per gram.
Take 2,000 kcal a day with 25% protein, 45% carbohydrates and 30% fat:
- Protein: 2,000 × 0.25 = 500 kcal, and 500 ÷ 4 = 125 g.
- Carbohydrates: 2,000 × 0.45 = 900 kcal, and 900 ÷ 4 = 225 g.
- Fat: 2,000 × 0.30 = 600 kcal, and 600 ÷ 9 ≈ 66.7 g, so about 67 g.
Check: 500 + 900 + 600 = 2,000 kcal. For someone weighing 70 kg (154 lb), 125 g of protein is about 1.8 g per kilogram, a little over twice the 0.8 g/kg RDA.
The macro presets
| Preset | Protein | Carbohydrates | Fat | Within the adult AMDR? |
|---|---|---|---|---|
| Balanced | 20% | 50% | 30% | Yes |
| High protein | 30% | 45% | 25% | Yes |
| Low carb | 30% | 25% | 45% | No — carbs below, fat above |
| Adult AMDR | 10–35% | 45–65% | 20–35% | — |
The balanced split sits near the middle of every AMDR and resembles a typical healthy eating pattern. High protein shifts calories from carbs and fat toward protein while staying inside the ranges, a common choice for people losing weight or lifting weights. Low carb cuts carbohydrates to a quarter of calories and makes up the difference with fat. It is a deliberate step outside the AMDR, so the calculator adds a note.
Macro chart by calorie level
Grams per day for each preset, calculated with the same formula as the calculator and rounded to the nearest gram.
| Calories | Balanced (P / C / F) | High protein (P / C / F) | Low carb (P / C / F) |
|---|---|---|---|
| 1,600 kcal | 80 / 200 / 53 g | 120 / 180 / 44 g | 120 / 100 / 80 g |
| 1,800 kcal | 90 / 225 / 60 g | 135 / 203 / 50 g | 135 / 113 / 90 g |
| 2,000 kcal | 100 / 250 / 67 g | 150 / 225 / 56 g | 150 / 125 / 100 g |
| 2,200 kcal | 110 / 275 / 73 g | 165 / 248 / 61 g | 165 / 138 / 110 g |
| 2,500 kcal | 125 / 313 / 83 g | 188 / 281 / 69 g | 188 / 156 / 125 g |
| 2,800 kcal | 140 / 350 / 93 g | 210 / 315 / 78 g | 210 / 175 / 140 g |
| 3,000 kcal | 150 / 375 / 100 g | 225 / 338 / 83 g | 225 / 188 / 150 g |
How to calculate macros for weight loss and muscle gain
For weight loss, the calorie target matters more than the exact split you choose in a macro calculator. Start from your maintenance calories from the TDEE calculator, subtract 250 to 500 kcal, and choose a split you can follow. A higher protein share helps many people stay full and preserve muscle while eating less.
Very low targets are another matter. Under about 1,200 kcal a day it becomes hard to meet vitamin and mineral needs from food, and very-low-calorie diets of around 800 kcal or less are meant to be followed only under medical supervision. The calculator shows a note below 1,200 kcal.
For weight gain or muscle building, add 250 to 500 kcal to maintenance and keep protein at a level that suits your training. Your BMR and body fat percentage can help put these numbers in context.
Common mistakes
- Mixing up calories and grams. 30% protein means 30% of calories, not 30% of the food’s weight.
- Using 4 kcal per gram for fat. Fat is 9 kcal per gram, so a fat target in grams is much smaller than a carb target with the same calories.
- Counting fiber twice. Food labels include fiber in total carbohydrates. Track total carbohydrates unless your plan specifically uses net carbs.
- Ignoring alcohol. Each gram provides about 7 kcal that sits outside the three macros.
- Changing the split before the calories. If weight is not moving, review the calorie target first.
Glossary
- Macronutrients. Nutrients needed in large amounts that provide energy: protein, carbohydrates and fat.
- AMDR (Acceptable Macronutrient Distribution Range). The range of calorie shares for each macro linked to adequate nutrition and lower chronic-disease risk in adults.
- RDA (Recommended Dietary Allowance). The daily intake that meets the needs of nearly all healthy people; for protein, 0.8 g per kilogram.
- TDEE (total daily energy expenditure). The calories you burn in a day, including activity; eating this amount keeps weight stable.
Worked examples
Balanced split at 2,400 kcal
A 2,400 kcal daily target with the balanced preset (20% protein, 50% carbs, 30% fat).
Inputs: Daily calories = 2400 kcal; Adjustment = None — calories above are my target; Macro split = Balanced (20% protein, 50% carbs, 30% fat)
Protein: 2,400 × 0.2 ÷ 4 kcal/g = 120 g Carbohydrates: 2,400 × 0.5 ÷ 4 kcal/g = 300 g Fat: 2,400 × 0.3 ÷ 9 kcal/g = 80 g
Answer: 2,400 kcal a day, balanced split: 120 g protein, 300 g carbs, 80 g fat. An estimate, not medical advice.
High protein for weight loss
Maintenance of 2,600 kcal minus 500 kcal, high-protein preset, for a 180 lb person.
Inputs: Daily calories = 2600 kcal; Adjustment = Subtract 500 kcal a day (weight loss); Macro split = High protein (30% protein, 45% carbs, 25% fat); Body weight (optional) = 180; Body weight (optional) unit = Pounds
Calorie target: 2,600 − 500 = 2,100 kcal Protein: 2,100 × 0.3 ÷ 4 kcal/g = 157.5 g Carbohydrates: 2,100 × 0.45 ÷ 4 kcal/g = 236.3 g Fat: 2,100 × 0.25 ÷ 9 kcal/g = 58.3 g
Answer: 2,100 kcal a day, high protein split: 158 g protein, 236 g carbs, 58 g fat. An estimate, not medical advice.
Custom split with uneven percentages
1,850 kcal with a custom 27.5% protein, 40% carbs, 32.5% fat split (carbs just under the AMDR).
Inputs: Daily calories = 1850 kcal; Adjustment = None — calories above are my target; Macro split = Custom percentages; Protein (custom) = 27.5 %; Carbohydrates (custom) = 40 %; Fat (custom) = 32.5 %
Protein: 1,850 × 0.275 ÷ 4 kcal/g = 127.2 g Carbohydrates: 1,850 × 0.4 ÷ 4 kcal/g = 185 g Fat: 1,850 × 0.325 ÷ 9 kcal/g = 66.8 g
Answer: 1,850 kcal a day, custom split: 127 g protein, 185 g carbs, 67 g fat. An estimate, not medical advice.
Assumptions and limitations
- This is an estimate, not medical advice. It divides the calories you enter; it does not estimate your calorie needs. Use the TDEE or calorie calculator for that, and talk to a doctor or registered dietitian if you have diabetes, kidney disease or another condition affected by diet.
- Energy factors are 4 kcal per gram of protein, 4 kcal per gram of carbohydrate and 9 kcal per gram of fat. Alcohol (7 kcal per gram) and fiber's lower energy value are not modeled.
- The adjustment adds or subtracts a fixed 250 or 500 kcal a day from the calories you enter. It does not predict how fast your weight will change.
- Presets: balanced is 20% protein, 50% carbs, 30% fat; high protein is 30% protein, 45% carbs, 25% fat; low carb is 30% protein, 25% carbs, 45% fat. Custom percentages must add up to 100%.
- Each split is compared with the adult Acceptable Macronutrient Distribution Ranges (protein 10–35%, carbohydrates 45–65%, fat 20–35%). A note appears when a share falls outside them or when the target is under 1,200 kcal a day.
- Grams are rounded to the nearest whole gram, so rebuilding calories from the rounded grams can differ by a few kcal.
Frequently asked questions
How do I calculate my macros?
Start with a daily calorie target. Multiply it by the percentage for each macro to get calories, then divide by 4 for protein and carbohydrates or by 9 for fat. At 2,000 kcal with 30% protein, that is 600 kcal ÷ 4 = 150 g of protein.
What is the best macro ratio for weight loss?
In a two-year trial comparing diets with different protein, carb and fat shares, weight loss was similar across all of them, so the calorie deficit matters more than the ratio. A higher protein share, around 25–30% of calories, can help you feel full and keep muscle while eating less. Pick a split you can stick with, and check it with a dietitian if you have a health condition.
How much protein do I need a day?
The adult RDA is 0.8 g per kilogram of body weight, which is the minimum to avoid deficiency for most people. Active people and older adults often aim higher. Enter your weight in the calculator to see how your protein target compares in grams per kilogram and per pound.
Why does fat have 9 calories per gram?
Fat is a more concentrated energy store than protein or carbohydrates. Each gram releases about 9 kcal when the body uses it, compared with about 4 kcal for a gram of protein or carbohydrate. That is why a small number of fat grams covers a large share of calories.
Is a low-carb split safe?
Many people follow low-carb diets without problems, but the low-carb preset puts carbs below and fat above the adult AMDR. If you take medicine for diabetes or blood pressure, or have kidney disease, talk to your doctor before cutting carbs sharply, because doses may need to change.
Where do I get my calorie target?
Use the [TDEE calculator](/tdee-calculator/) to estimate your maintenance calories from your size, age and activity, then enter that number here and pick an adjustment. If you already have a target from a dietitian or app, enter it with no adjustment.
Should macros be the same every day?
They do not have to be. Many people eat more carbohydrates on training days and fewer on rest days while keeping weekly totals similar. A daily target is simply easier to track, so start there and adjust once you are consistent.
Sources
- Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids — Institute of Medicine, The National Academies Press. Checked October 10, 2026.
- Food and Nutrition Information Center (FNIC) — calories per gram of carbohydrate, protein and fat — USDA National Agricultural Library. Checked October 10, 2026.
- Optimizing Protein Intake in Adults: Interpretation and Application of the Recommended Dietary Allowance Compared with the Acceptable Macronutrient Distribution Range — Advances in Nutrition (Wolfe et al., 2017), via PubMed. Checked October 10, 2026.
- Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates — New England Journal of Medicine (Sacks et al., 2009), via PubMed. Checked October 10, 2026.
- Dictionary definition: very low-calorie diet — National Institute of Diabetes and Digestive and Kidney Diseases (NIH). Checked October 10, 2026.