Macro Split Calculator
Turn a daily calorie target and a macro ratio (balanced, high-protein, low-carb, or keto) into grams of protein, carbs, and fat. Runs entirely in your browser.
Daily macros
| Macro | Grams | kcal | % |
|---|---|---|---|
| Protein | 150 g | 600 | 30% |
| Carbs | 200 g | 800 | 40% |
| Fat | 67 g | 600 | 30% |
Grams = (calories × macro %) ÷ energy density, using Atwater factors: protein and carbs 4 kcal/g, fat 9 kcal/g. Not medical or dietary advice.
About this tool
Once you know your daily calorie target, a macro split tells you how to divide those calories among the three macronutrients — protein, carbohydrate, and fat — and converts each share into grams to hit on your food labels. This calculator uses the Atwater energy factors that nutrition labels are based on: protein and carbohydrate provide about 4 calories per gram, and fat about 9. So for a chosen percentage split it multiplies your calories by each macro's share and divides by its calorie density to get grams. Presets cover the common patterns — a balanced 30/40/30, a high-protein 40/40/20, a low-carb 40/20/40, and a 25/5/70 ketogenic split — and a stacked bar shows the proportions at a glance. It is a planning tool: the right split depends on your goals, activity, and preferences, and total calories matter more than the exact ratio for most outcomes. It is informational, not medical or dietary advice. Everything runs in your browser.
How to use it
- Enter your daily calorie target (from the calorie calculator or your plan).
- Pick a macro split that matches your approach.
- Read the grams of protein, carbs, and fat to aim for each day.
- Track your intake against those gram targets.
Frequently asked questions
- How are the grams calculated?
- Grams = (calories × macro percentage) ÷ calories-per-gram, where protein and carbs are 4 kcal/g and fat is 9 kcal/g (the Atwater factors used on nutrition labels). For 2000 kcal at 30% protein, that is 600 kcal ÷ 4 = 150 g protein.
- Why is fat 9 calories per gram?
- Fat is more energy-dense than protein or carbohydrate — about 9 kcal per gram versus 4 — so a given percentage of calories from fat translates to fewer grams. That is why a high-fat keto split still shows a moderate fat gram count.
- Which macro split should I choose?
- It depends on goals and preference. Balanced (30/40/30) suits most people; higher protein supports muscle retention and satiety; low-carb or keto can help some with appetite control. Evidence shows total calories and adequate protein matter most; the rest is largely preference and adherence.
- Is keto right for everyone?
- No. A 5%-carb ketogenic split works for some but is restrictive, can cause an initial adjustment period, and is not advisable for certain conditions or for many athletes who need carbohydrate for performance. Choose a split you can sustain and that fits your health needs.
- Do the percentages have to add to 100?
- Yes — the three macros together account for all your calories, so the split must total 100%. The presets here all do; if you build a custom split, ensure the shares sum to 100.
- Is this medical or dietary advice?
- No. It is an informational planning tool. For a personalized nutrition plan or any medical condition, consult a registered dietitian or physician.