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Fitness & Weight
Macro Calculator — Protein, Carbs & Fat Grams Per Day
Split your daily calories into protein, carbs and fat — in grams you can actually track
A macro calculator turns a daily calorie number into the three macronutrients you actually log in an app: protein, carbohydrates and fat, measured in grams. "Macros" is short for macronutrients, and counting them is just calorie counting with more detail — instead of one number, you aim for three, which helps protect muscle on a cut and fuel training on a bulk.
The whole thing rests on two facts. Protein and carbs each provide 4 calories per gram, and fat provides 9 calories per gram. That's the conversion that ties calories to grams. If you know what percent of your calories should come from each macro, the grams fall right out:
Grams = (calories × percent) ÷ calories-per-gram.
Worked example. Say you eat 2,000 calories a day on a balanced 30/40/30 split (protein/carbs/fat): • Protein = (2,000 × 0.30) ÷ 4 = 600 ÷ 4 = 150 g • Carbs = (2,000 × 0.40) ÷ 4 = 800 ÷ 4 = 200 g • Fat = (2,000 × 0.30) ÷ 9 = 600 ÷ 9 ≈ 67 g
Add the calories back up — 600 + 800 + 600 = 2,000 — and it checks out. That self-check (grams × calories-per-gram should return your daily total) is the fastest way to catch an error.
Don't know your calorie target? This tool can estimate it for you. Enter your sex, age, height in feet and inches, weight in pounds, and activity level, and it finds your TDEE (Total Daily Energy Expenditure) using the Mifflin-St Jeor equation, then adjusts for your goal: roughly −500 calories for a cut (about 1 lb/week) or +300 to +500 for a lean bulk.
The most common mistake is percentages that don't add to 100% — 40/40/30 is 110% and will overshoot your calories. The second is forgetting that fat is 9 cal/g, not 4, which makes people wildly overestimate fat grams. A higher-protein split (like 40/40/20) is popular for fat loss because protein keeps you full and helps preserve lean mass.
This is an informational estimate, not medical or nutrition advice. Real needs vary with body composition, training, health conditions and medications. For a plan tailored to you, talk with a registered dietitian or your doctor.
Calculator
Fill in the fields and click "Calculate" for instant results.
📰 Formula
• Calories per gram: protein 4 · carbs 4 · fat 9 • Protein (g) = (calories × protein%) ÷ 4 • Carbs (g) = (calories × carb%) ÷ 4 • Fat (g) = (calories × fat%) ÷ 9 • Splits add to 100%: protein% + carb% + fat% = 100 • Optional TDEE (Mifflin-St Jeor, metric): BMR = 10×kg + 6.25×cm − 5×age + s (s = +5 men, −161 women); TDEE = BMR × activity factor • Goal adjustment: cut ≈ TDEE − 500 · maintain = TDEE · bulk ≈ TDEE + 400
📰 Formula
• Calories per gram: protein 4 · carbs 4 · fat 9 • Protein (g) = (calories × protein%) ÷ 4 • Carbs (g) = (calories × carb%) ÷ 4 • Fat (g) = (calories × fat%) ÷ 9 • Splits add to 100%: protein% + carb% + fat% = 100 • Optional TDEE (Mifflin-St Jeor, metric): BMR = 10×kg + 6.25×cm − 5×age + s (s = +5 men, −161 women); TDEE = BMR × activity factor • Goal adjustment: cut ≈ TDEE − 500 · maintain = TDEE · bulk ≈ TDEE + 400
🧪 Worked examples
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Example 2
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Example 3
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Example 4
⚠️ Common mistakes
- Using percentages that don't add to 100% (40/40/30 = 110%, which overshoots calories).
- Dividing fat by 4 instead of 9 — fat is 9 calories per gram.
- Confusing your goal calories with TDEE; subtract for a cut, add for a bulk first.
- Forgetting that the same grams can come from very different foods — quality still matters.
💡 Tips
- Anchor protein first (roughly 0.7–1 g per pound of body weight for active people), then fill carbs and fat.
- Always sanity-check: grams × cal/g for all three should add back to your daily calories.
- Pick a split you can actually stick to — adherence beats the 'perfect' ratio every time.
Embed this calculator on your site
Copy the code below and paste it into the HTML of your site or blog.
<iframe src="https://www.calcnimbus.com/embed/macro-calculator" width="100%" height="500" frameborder="0" style="border:1px solid #eee;border-radius:12px"></iframe>
❓ Frequently asked questions
What are macros?
Macros (macronutrients) are protein, carbohydrates and fat — the three nutrients that supply calories. Protein and carbs give 4 calories per gram, fat gives 9. Counting macros is calorie counting split into those three numbers.
How do I calculate my macros?
Start with your daily calories, then split them by percent: Protein g = (calories × protein%) ÷ 4, Carbs g = (calories × carb%) ÷ 4, Fat g = (calories × fat%) ÷ 9. For 2,000 cal at 30/40/30 you get 150 g protein, 200 g carbs, 67 g fat.
What is a good macro split for losing weight?
A higher-protein split such as 40/40/20 (protein/carbs/fat) is popular for cutting because protein keeps you full and helps preserve muscle. Pair it with a calorie deficit of roughly 500 calories a day for about 1 lb of loss per week. This is general info, not personalized advice.
How much protein should I eat per day?
A common range for active adults trying to keep or build muscle is about 0.7 to 1 gram of protein per pound of body weight. A 170-lb person would aim for roughly 120–170 g. Needs vary, so treat this as a starting estimate.
How many calories are in a gram of protein, carbs and fat?
Protein has 4 calories per gram, carbohydrates have 4 calories per gram, and fat has 9 calories per gram. Alcohol, if you count it, has about 7 per gram but isn't a macro.
What is TDEE and how does this calculator find it?
TDEE is your Total Daily Energy Expenditure — the calories you burn in a day. The tool estimates your BMR with the Mifflin-St Jeor equation from your sex, age, height and weight, then multiplies by an activity factor (1.2 sedentary up to about 1.9 very active).
Should I subtract calories for a cut before splitting macros?
Yes. Set your goal calories first — roughly TDEE minus 500 for a cut or TDEE plus 300–500 for a lean bulk — then split that target into protein, carbs and fat. Splitting your maintenance number won't create a deficit or surplus.
Do I have to hit my macros exactly every day?
No. Getting within about 5–10 grams of each target is plenty for most people, and protein is the one most worth hitting consistently. Weekly averages matter more than any single day.
Is this macro calculator medical or nutrition advice?
No. It's an informational estimate based on standard equations and calorie-per-gram values. Your real needs depend on body composition, training, health conditions and medications. For a tailored plan, see a registered dietitian or your doctor.