Macro Calculator
Get your daily protein, carb, and fat targets in grams. Your calories come from your TDEE and goal, then split them the way that fits how you eat and train.
Your details
Moderate exercise 3–5 days/week. Pick the level that matches your training, not your ambitions — when in doubt, go one level lower.
A solid default for most goals — enough protein to hold muscle, enough carbs to train.
Daily calorie target
2,150
kcal/day · lose fat · 2,690 kcal TDEE
- Protein
- 161g
- Carbs
- 215g
- Fat
- 72g
30% · 645 kcal
40% · 860 kcal
30% · 645 kcal
Per meal, across 4 meals
Useful for building a plate — you do not need to hit these exactly at every meal.
538
kcal
40g
Protein
54g
Carbs
18g
Fat
Protein check
This split puts you at 2.1 g of protein per kg of body weight. For this goal, research generally supports 1.6–2.4 g/kg. That sits comfortably in range.
Knowing your macros is the easy part — hitting them daily is the work. Snap a photo of your plate and 2BIB logs the protein, carbs, and fat for you.
How your macros are calculated
Macros are downstream of calories, so the calculation runs in three steps — and every step is visible above, not hidden behind a black box.
- 1
Estimate your daily burn
Your BMR comes from the Mifflin-St Jeor equation, then gets multiplied by an activity factor between 1.2 and 1.9 to give your TDEE — the calories you burn on an average day.
- 2
Apply your goal
Fat loss sets calories 20% below TDEE; muscle gain sets them 10% above; weight gain 15% above; maintenance sits at TDEE. These are conventional, sustainable adjustments rather than crash-diet numbers.
- 3
Split into grams
The chosen percentage split is divided by the energy density of each macro — 4 kcal per gram for protein and carbohydrate, 9 kcal per gram for fat — to give your daily grams.
Grams from a percentage split
Protein & carbohydrate
grams = (calories × split %) ÷ 4
Fat
grams = (calories × split %) ÷ 9
What each macro actually does
Calories decide whether your weight moves. Macros decide what that weight is made of — and how good you feel getting there. Read more on building balanced nutrition around these three.
Protein
4 kcal/gRepairs and builds muscle, and keeps you full for longest. It is the macro to protect when calories come down — in a deficit, too little protein means the weight you lose includes muscle you wanted to keep.
Common sources · Chicken, fish, eggs, Greek yoghurt, lean beef, tofu, lentils, whey
Carbohydrate
4 kcal/gYour body's preferred training fuel. Cutting carbs hard often drops the scale quickly through water loss, then quietly costs you gym performance and recovery.
Common sources · Rice, oats, potatoes, pasta, bread, fruit, beans
Fat
9 kcal/gEssential for hormone production and absorbing vitamins A, D, E, and K. Keep it above roughly 0.6 g per kg of body weight — very low-fat diets tend to feel bad and be hard to sustain.
Common sources · Olive oil, nuts, avocado, oily fish, eggs, cheese
The hard part is not the maths
Working out your macros takes thirty seconds. Hitting them every day for a month is the part that beats people — mostly because manual logging means weighing food, searching databases, and guessing at restaurant portions.
That is the friction 2BIB removes. Point your camera at a plate and GPT-4o vision identifies each item, estimates the portions, and logs the protein, carbs, and fat. Nutrition labels are read by OCR, and packaged food scans by barcode — unlimited on every plan.
Log macros from a photo
Free accounts get unlimited AI scans for the first 7 days, then 7 scans a month — plus unlimited barcode lookups, macro tracking, and 7-day history. No card required.
Macro calculator FAQ
What is a good macro split?
A balanced 30% protein / 40% carbs / 30% fat suits most people. Cutting? A higher-protein 40/35/25 protects muscle and keeps you fuller. Training for endurance? More carbs, around 25/50/25. No split is magic — calories drive weight change, and the split shapes body composition, training quality, and how sustainable the plan feels.
How much protein do I need per day?
Roughly 1.6–2.2 g per kg of body weight if you train, rising toward 2.4 g/kg in an aggressive deficit. Sedentary adults need less — about 1.2–1.6 g/kg. The calculator shows your protein in g/kg so you can sanity-check the split rather than trusting a percentage blindly.
How many calories are in a gram of each macro?
Protein and carbohydrate are about 4 kcal per gram; fat is about 9 kcal per gram. Alcohol is about 7 kcal per gram and is not tracked as a macro. That density difference is why fat targets look small in grams next to carbs.
Do I have to hit my macros exactly every day?
No — within about 5–10 g of your protein target, with calories close, is plenty. Weekly averages matter far more than any single day. Chasing perfect daily numbers is the fastest way to give up on tracking altogether.
Should my macros change as I lose weight?
Yes. Macros come from calories, calories come from TDEE, and TDEE falls as you lose weight. Recalculate every 5–10 kg — or let 2BIB recalibrate from your logged weight so the targets move with you.
Is this macro calculator free?
Yes — no signup, no email. 2BIB then does the harder part: logging those macros from a photo of your plate, on a free plan.
This calculator is for general education, not medical advice. If you are pregnant, managing a health condition, or working with a clinician, follow their guidance on intake.
Your macros, tracked automatically.
2BIB logs protein, carbs, and fat from a photo of your meal — and adapts your targets as your weight changes. Free to start, on iPhone and the web.