Macro Calculator
Split a daily calorie target into carbohydrate, protein and fat in grams.
Your figures
Result
How to use this tool
- Enter your own figures over the defaults — Daily calories, Split.
- The answer updates as you type. There is no button, and nothing is sent anywhere.
- Change Daily calories on its own to see how much it moves the result — the worked example below shows exactly that.
Carbohydrate and protein provide 4 calories per gram, fat provides 9. That difference is why the fat figure in grams always looks small relative to its percentage.
How it works
This takes 2 inputs — daily calories, split — and returns carbohydrate, protein, fat and split. The whole calculation happens in this page as you type: there is no submit button, no request, and nothing stored.
Because it recalculates on every keystroke you can use it as a sensitivity test rather than a one-shot answer. Moving daily calories alone from 2,200 to 2,420 changes carbohydrate from 220 g to 242 g — the worked example below sets that out in full.
A worked example
Worked through with the figures the page already has in it: daily calories of 2,200 kcal and split of Balanced 40/30/30, giving carbohydrate of 220 g. These numbers come from running the calculator’s own code, not from being typed in here, so they cannot drift away from what you see on screen.
Starting from:
- Daily calories: 2,200 kcal
- Split: Balanced 40/30/30
| Result | Value |
|---|---|
| Carbohydrate | 220 g |
| Protein | 165 g |
| Fat | 73 g |
| Split | 40% / 30% / 30% |
What happens when one input moves
Holding everything else steady and changing Daily calories from 2,200 kcal to 2,420 kcal — 10% — moves the answer like this:
| Figure | 2,200 kcal | 2,420 kcal |
|---|---|---|
| Carbohydrate | 220 g | 242 g |
| Protein | 165 g | 182 g |
| Fat | 73 g | 81 g |
| Split | 40% / 30% / 30% | 40% / 30% / 30% |
That is usually the number worth arguing over: it is easier to move than the headline amount, and the difference compounds across the whole term.
Macro Calculator — frequently asked questions
What split should I use?
It depends on goals and preference. Higher protein helps preserve muscle in a deficit. Beyond that, adherence matters more than the exact ratio.
How much protein do I need?
General guidance is 1.6–2.2 g per kg of body weight for those training regularly; less for sedentary adults.
Why is the fat number so small?
Fat carries 9 calories per gram against 4 for carbs and protein, so the same percentage of calories is fewer grams.
Is this calculator free?
Yes, with no account, no limits and no data collection. It runs entirely in your browser.
Should I rely on this for a financial or medical decision?
No. It is a planning estimate built on standard formulas and stated assumptions. For decisions that matter, speak to a qualified professional who can account for your full circumstances.
How accurate is the Macro figure?
The arithmetic is exact. With the defaults on this page — daily calories 2200 kcal, split Balanced 40/30/30 — it returns carbohydrate of 220 g. What limits accuracy is the assumptions, not the maths: change daily calories to 2420 kcal and the same formula gives 242 g. Treat it as a well-founded estimate, not a quotation.
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Nothing is sent anywhere. The figures you type stay in this page and are never transmitted or stored — how that works.
Disclaimer. The formula is exact; the answer is only as good as the figures and assumptions above. Not financial, tax, medical or legal advice. Full disclaimer.