Macro Split Calculator
This free macro split calculator turns your daily calories and macro percentages into exact protein carbs fat grams — plus the calories behind each macro and per-meal targets — using the classic 4-4-9 calorie math. Whether you count macros for flexible dieting, muscle gain, or a cut, enter any protein/carbs/fat split and get your daily gram targets instantly.
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Enter your calories and macro split to see your daily gram targets.
How to use this calculator
Start with your daily calorie target. If you don't know it yet, our TDEE calculator estimates it from your weight, height, age, and activity level. Then set the share of calories coming from protein, carbs, and fat. The default 30 / 40 / 30 split is a balanced starting point used by many flexible-dieting plans — type any split, from 40/30/30 to 20/50/30, and every number updates instantly.
The three percentages must add up to 100%. If they don't, an error message shows your current total and the results hide until the split is complete. The optional meals-per-day box (default 3) divides each macro into per-meal gram targets, handy for planning plates without extra math.
Use the per-meal column to build your day: for example, if the tool says 50 g of protein per meal, aim for a palm-sized portion of meat, fish, eggs, or legumes plus protein at breakfast and snacks. The protein intake calculator can sanity-check your protein number against your body weight and training goal.
How it works
The math rests on the Atwater factors — the energy values used on nutrition labels: protein and carbohydrates each contain about 4 calories per gram, while fat contains about 9. The macro split calculator first works out how many of your calories come from each macro, then converts those calories into grams:
protein_g = kcal × protein% ÷ 4 · carbs_g = kcal × carbs% ÷ 4 · fat_g = kcal × fat% ÷ 9
For example, 2,000 calories at 30% protein, 40% carbs, and 30% fat means 600 kcal of protein (600 ÷ 4 = 150 g), 800 kcal of carbs (800 ÷ 4 = 200 g), and 600 kcal of fat (600 ÷ 9 = 66.7 g, shown as 67 g). Grams are rounded to the nearest whole number, so totals may shift by a gram — that's normal.
Per-meal targets are simply each daily macro divided by your number of meals, rounded to the nearest gram. These figures are general information, not medical advice — talk to a doctor or registered dietitian before making major diet changes, especially if you have a medical condition.
Frequently asked questions
What is a good macro split?
A common starting point is 30% protein, 40% carbs, and 30% fat. The right split depends on your goal: people building muscle often go higher in protein, endurance athletes lean toward more carbs, and low-carb approaches raise the fat share. Enter any split above and this macro split calculator converts it to grams so you can compare plans and adjust based on energy and results.
How do you convert macro percentages into grams?
Multiply your daily calories by each macro's percentage, then divide by its calories per gram: protein and carbs have 4 calories per gram and fat has 9. For example, 30% of 2,000 calories is 600 calories of protein, and 600 / 4 = 150 g. This macro split calculator does that conversion for all three macros instantly, including per-meal grams.
Why does fat use 9 calories per gram?
Fat is more energy-dense than protein or carbohydrates. Protein and carbs each provide about 4 calories per gram, while fat provides about 9 — the Atwater factors used in nutrition labeling. That is why the same percentage of fat yields far fewer grams than the same percentage of protein or carbs.
Is this macro split calculator medical advice?
No. This tool gives general information only, using the standard 4-4-9 calorie math for protein, carbs, and fat. It is not medical or nutrition advice. Talk to a doctor or registered dietitian before making major diet changes, especially if you have a medical condition.