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.)
When to use this tool
This tool is designed for quick, practical tasks such as everyday calculations, data formatting, or simple conversions. It is best used when you need fast results without installing software or using complex tools.
When to use
- Quick checks or one-time calculations
- Validating or converting data before using it elsewhere
- Simple tasks that do not require advanced software
When not to use
- Critical financial, legal, or medical decisions
- Large-scale or automated processing
- Situations requiring guaranteed precision beyond basic validation
Always review results before using them in important contexts.
About this tool
This tool helps you perform quick utility operations directly in your browser. It runs entirely in your browser without sending data to a server.
You can use this tool when handling simple tasks without installing additional software. The results should be interpreted as a processed output based on your input data.
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.