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Macro calculator
Your daily calories, protein, carbs, and fat — then plan real days of eating against them in the free meal planner. Free, in your browser, nothing uploaded.
Fill in age, weight, and height to see your numbers.
Everything on this page saves to this device only — nothing is uploaded or tracked.
Now plan the eating
The free meal planner uses the targets from this calculator — build days of meals, copy a day across the week, and scan barcodes as you shop.
Open the free meal plannerNo signup — it saves to this device, like the calculator.
How it works
1 — BMR. The Mifflin-St Jeor equation estimates the calories your body burns at complete rest from your sex, age, height, and weight. It's the equation dietitians default to because it stays accurate across body types.
2 — TDEE. Multiplying BMR by an activity factor (1.2 for a desk life up to 1.9 for hard daily training) gives your total daily energy expenditure — the calories that keep your weight where it is.
3 — Goal. A cut takes 20% off, a lean cut 10%, a lean bulk adds 10%. Moderate on purpose: aggressive deficits shed muscle and rebound; aggressive surpluses add mostly fat.
4 — The split. Protein lands at 1.6 g per kg of body weight, fat at 25% of calories, and carbs get everything left. Protein protects muscle, fat covers hormones, carbs fuel the training that makes the whole plan work.
Want the full reasoning, a worked example, and how to hit the numbers day to day? Read the macro guide.
Common questions
How are the calories calculated?
The calculator uses the Mifflin-St Jeor equation for your basal metabolic rate (BMR), multiplies it by an activity factor (1.2 sedentary up to 1.9 for athletes) to get your maintenance calories (TDEE), then applies your goal: −20% for a cut, −10% for a lean cut, +10% for a lean bulk.
How is the protein / carb / fat split chosen?
Protein is set at 1.6 g per kg of body weight — the evidence-based sweet spot for keeping or building muscle. Fat gets 25% of your calories, enough for hormones and satiety. Carbs get every remaining calorie, because they fuel training.
Do I need an account to use it?
No. The calculator is free and runs entirely in your browser. Your inputs are saved to your device's local storage so they're still here next visit — nothing is uploaded or tracked.
Can I plan my meals against these targets?
Yes — the free meal planner on this site picks your targets up automatically. It's a real calendar-based planner: add foods to breakfast, lunch, dinner, and snacks on any date by searching the same USDA food library the RepDriver app uses (with photos and real serving sizes), scanning a packaged food's barcode with your phone's camera, or quick-adding custom macros — then copy a finished day onto as many other days as you like and tweak each one. Like the calculator, it needs no account and saves to your device.
What's the recommended weight range it shows?
It's the healthy-BMI band for your height: BMI 18.5–24.9 for adults, and a slightly higher 23–29.9 band at 65+, where research links a slightly higher weight with lower risk. It's a population-level guide, not a diagnosis — muscular people in particular can sit above it while being perfectly healthy.
What do I do with these numbers?
Hit them, most days. Weigh or estimate portions, add up the macros of what you eat, and land near the targets. A tracker makes that arithmetic automatic — RepDriver's free macro counter checks your day against these exact targets using a USDA food library.
Numbers are the easy part. Hitting them is the game.
RepDriver's free macro counter tracks every meal against these targets — 200+ USDA foods with photos, custom foods, and day-by-day meal planning.
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