Macro Calculator Calculators
Split a daily calorie target into protein, carbs and fat.
Macro Calculator is a free online tool that split a daily calorie target into protein, carbs and fat. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Calculators
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- plain JavaScript
- Settings
- 2
- Works offline
- Yes, after the first visit
About Macro Calculator
Protein and carbohydrate provide about 4 kcal per gram, fat about 9 — which is why fat-heavy splits produce much smaller gram numbers for the same calories. Protein is the macro worth getting right: roughly 1.6 g per kg of bodyweight supports muscle retention in a deficit, and the rest is largely preference.
How to use it
- Enter daily calories and split.
- Results update the moment anything changes.
The 2 settings
| Setting | What it does | Default |
|---|---|---|
| Daily calories | Range 500–10000. | 2200 |
| Split | Choose from 5: Balanced — 30P / 40C / 30F, High protein — 40P / 40C / 20F, Higher carb — 25P / 50C / 25F, Lower carb — 35P / 25C / 40F, Keto — 30P / 10C / 60F. | Balanced — 30P / 40C / 30F |
Under the hood
| Runs on | plain JavaScript — runs the whole thing |
| Controls | Daily calories, Split |
Questions
Do macro ratios matter for weight loss?
Total calories drive weight change; macros drive body composition, satiety and how you feel. Adequate protein and a split you can actually stick to beat any theoretically optimal ratio.
What does the split option change?
It offers 5 choices — Balanced — 30P / 40C / 30F, High protein — 40P / 40C / 20F, Higher carb — 25P / 50C / 25F and Lower carb — 35P / 25C / 40F and more. The default is Balanced — 30P / 40C / 30F, which suits most cases; change it when your input or your destination calls for something specific.
What are the limits on daily calories?
It accepts 500 to 10000, starting at 2200.
Is the arithmetic exact?
It uses double-precision floating point — about 15 significant figures, far more than the inputs justify. Displayed rounding is cosmetic; the underlying numbers are not rounded between steps, so chained results do not drift.