Macro Calculator
Turn your calorie target into daily protein, carb, and fat grams.
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A macro calculator translates your daily calorie target into grams of protein, carbohydrate, and fat — the three macronutrients that make up everything you eat. It starts from your maintenance calories (TDEE) using the Mifflin–St Jeor equation, adjusts for your goal, then splits the total by the diet ratio you choose.
Pick a preset — balanced, low-carb, high-protein, or keto — or set a custom split. Everything runs in your browser, so your details never leave your device, and the result shows both the percentages and the grams to eat each day.
Formula
Calories first (BMR → TDEE → goal)
BMR = 10·kg + 6.25·cm − 5·age (±sex); TDEE = BMR × activity; goal = TDEE ± 500
Maintenance calories come from Mifflin–St Jeor scaled by activity. Losing or gaining shifts the target by about 500 kcal/day (≈ 1 lb/week), never below a safe minimum.
Calories per gram (Atwater factors)
protein = 4 kcal/g · carbs = 4 kcal/g · fat = 9 kcal/g
Fat is more than twice as energy-dense as protein or carbs, which is why a higher-fat plan (like keto) has fewer total grams of food energy from carbs.
Grams from a ratio
grams = (calories × macro%) ÷ kcal-per-gram
For a 2,000-calorie day at 30% protein: 2,000 × 0.30 = 600 protein calories ÷ 4 = 150 g protein.
Examples
| Example | Input | Result |
|---|---|---|
| Balanced, maintain | M 30y, 80kg, 180cm, moderate | 2,759 kcal · 207P / 276C / 92F |
| Keto, maintain | Same person | 172P / 34C / 215F (g) |
| High protein, lose | Same person, lose | 2,259 kcal · 226P / 169C / 75F |
How to use the macro calculator
- 1Enter your sex, age, weight, and height, and choose your activity level.
- 2Pick a goal: lose, maintain, or gain weight.
- 3Choose a diet preset (balanced, low-carb, high-protein, or keto) — or select Custom and set your own carb/protein/fat percentages.
- 4Read your daily calories and the protein, carb, and fat grams to aim for.
What are macros?
“Macros” is short for macronutrients — protein, carbohydrate, and fat — the nutrients your body needs in large amounts and the only ones (besides alcohol) that provide calories. Protein builds and repairs tissue and is the most satiating macro; carbohydrate is the body's preferred quick energy source; fat supports hormones, absorbs certain vitamins, and provides slow-burning energy. Tracking macros, not just calories, helps make sure the calories you eat actually support your goal.
Two people eating the same calories can get very different results depending on the split. A higher-protein plan, for instance, tends to preserve muscle in a calorie deficit and keep you fuller, which is why it's popular for fat loss. This tool sets the calorie budget first, then divides it the way you choose.
Choosing a macro split
There's no single best ratio — the right one depends on your goal, preferences, and how you train. A balanced 40% carb / 30% protein / 30% fat split works well for general health and most activity levels. A high-protein split (around 40% protein) suits anyone lifting weights or losing fat who wants to hold onto muscle. Low-carb (about 25% carbs) can help with appetite control, while keto (roughly 5% carbs, 70% fat) shifts the body toward burning fat for fuel and is followed for specific reasons.
Whichever you pick, protein is the macro worth anchoring first — a common target is 0.7–1 gram per pound of bodyweight when active. The calculator's presets already lean protein-forward for the fat-loss and high-protein options, but you can always switch to Custom to dial in your own numbers.
How to hit your macros
Start by getting protein at most meals — meat, fish, eggs, dairy, legumes, or a shake. Build the rest of the plate from carbs and fats according to your split, and use a food-tracking app for a couple of weeks until you can eyeball portions. You don't need to hit the grams perfectly every day; being consistently close is what drives results.
Recalculate when your weight changes meaningfully, since your calorie target — and therefore your grams — will shift with it. For the calorie target on its own, use the [Calorie Calculator](/tools/calorie-calculator); to see just your maintenance burn, see the [TDEE Calculator](/tools/tdee-calculator).
This calculator provides general estimates for educational use and is not medical or nutritional advice. Macro needs vary by individual. Consult a doctor or registered dietitian before making significant dietary changes, especially if you have a health condition.
Frequently asked questions
What are good macros for losing weight?
A higher-protein split helps preserve muscle in a deficit. Many people do well around 40% protein, 30% carbs, 30% fat at a calorie target about 500 below maintenance. Choose the High protein preset and the Lose goal above.
How much protein should I eat?
When active, a common target is 0.7–1 gram of protein per pound of bodyweight. The presets here are protein-forward; switch to Custom to set an exact percentage.
What are keto macros?
Keto is very low carb and high fat — roughly 5% carbs, 25% protein, 70% fat — to shift the body toward burning fat for fuel. Select the Keto preset to see your grams.
Do I have to hit my macros exactly?
No. Being consistently close (within 5–10 grams) is what matters. Prioritise protein, then fit carbs and fat around it.
Does this calculator store my data?
No. Every calculation runs locally in your browser — nothing you enter is uploaded, logged, or stored.
Embed this calculator
Add the Macro Calculator to your own website — free. Copy and paste this snippet:
<iframe src="https://numvella.com/embed/macro-calculator" width="100%" height="460" style="border:1px solid #e2e8f0;border-radius:12px" title="Macro Calculator — Numvella" loading="lazy"></iframe>Related calculators
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