Macro Split Calculator
Turn your daily calorie goal into precise protein, carb, and fat targets. Enter your calories and preferred macro percentages to see exactly how many grams of each macronutrient to eat each day.
How it works
The calculator splits your total daily calories across protein, carbohydrates, and fat based on the percentages you choose. First it converts each percentage into calories: macro calories = total calories × (macro % ÷ 100).
It then converts those calories to grams using the standard energy values: protein and carbohydrates provide 4 kcal per gram, while fat provides 9 kcal per gram. So grams = macro calories ÷ kcal-per-gram.
For best results your three percentages should add up to 100%. The tool will still calculate if they don't, but it flags the total so you can adjust.
Tips
Common starting splits are 40/30/30 (carb/protein/fat) for general fitness or 30/40/30 for higher-protein goals — adjust to your needs and how you feel.
Aim for roughly 1.6–2.2 g of protein per kg of body weight if you train regularly, then fill remaining calories with carbs and fat to hit your goal.
FAQ
Why do protein and carbs use 4 calories per gram but fat uses 9?
These are the Atwater general factors for the energy content of macronutrients. Fat is more energy-dense, providing about 9 kcal per gram, while protein and carbohydrates each provide about 4 kcal per gram.
What if my percentages don't add up to 100%?
The calculator still computes grams from each percentage, but it shows the total so you can correct it. For an accurate split, make sure protein, carb, and fat percentages sum to 100%.
What's a good macro split for losing weight?
There's no single answer, but a higher-protein split (e.g. 30–40% protein) helps preserve muscle and keeps you full during a calorie deficit. Combine it with an overall calorie target below your maintenance.