Macro Calculator
Convert a daily calorie target and macro split into grams of protein, carbs, and fat. Informational only.
Informational only (not medical advice). Privacy: runs locally in your browser. No inputs are stored or sent to a server.
How it works
This tool converts energy targets into grams using standard energy density values: protein 4 kcal/g, carbs 4 kcal/g, fat 9 kcal/g. If you enter kJ, it converts to kcal using 1 kcal = 4.184 kJ.
Formula (for each macro):
macro_kcal = total_kcal × (macro% ÷ 100)
grams = macro_kcal ÷ kcal_per_gram
Examples
- 2,000 kcal at 30/40/30 → protein 150g, carbs 200g, fat 67g (approx.)
- 2,500 kcal at 25/50/25 → protein 156g, carbs 313g, fat 69g (approx.)
FAQ
- What does this macro calculator do?
It converts your daily calorie target and macro split (protein/carbs/fat %) into grams per day using standard calories-per-gram values.
- What calories-per-gram values are used?
Protein = 4 kcal/g, Carbs = 4 kcal/g, Fat = 9 kcal/g.
- Do the macro percentages have to add up to 100%?
Yes. This tool validates that protein + carbs + fat equals 100%.
- Can I use kilojoules (kJ) instead of calories?
Yes. The tool can accept kJ and converts to kcal internally using 1 kcal = 4.184 kJ.
- Is my data stored?
No. All calculations run locally in your browser. Inputs are not sent to a server.