Add your age, height and weight, that's all it needs
How the split works
Protein comes first, set from your body weight, goal and how hard you train, because it's what keeps and builds muscle. Fat takes about a quarter of your calories to keep hormones happy. Carbs fill everything left over as fuel, which is why they're the number that moves most when your goal or training changes.
Targets, not a test. Protein is the one to prioritise, and your weight trend over a few weeks is the real feedback
Your macros, counted for you
Move, fuel and recovery in one app. You set the goal, Biofaze counts every gram against these targets as you log
Not sure yet? See what's inside BiofazeCommon questions
What are macros?
The three nutrients food is made of: protein, carbohydrates and fat. Protein builds and keeps muscle, carbs are your main fuel, and fat runs hormones and helps absorb vitamins. Hitting sensible gram targets for each, inside the right calories, is what people mean by counting macros.
How much protein do I need?
Sports nutrition research generally lands between 1.6 and 2.2 grams per kilogram of body weight for active people. This calculator scales yours with both goal and activity, from 1.6 g per kg for sedentary maintenance up to a 2.2 cap for hard training or a deficit, because both raise what your muscle needs. The exact figure it used is always shown under your macros.
How is the split worked out?
Protein is set first from your body weight, goal and activity, fat takes about 25% of your calories, and carbs fill whatever is left as fuel, which is why very active days carry a lot of carbs, exactly as sports nutrition prescribes. Calories come from the same Mifflin-St Jeor maths as our TDEE calculator, so the two pages always agree. The working is shown right here so you can check it.
Why do macro calculators give different numbers?
The calories usually agree, since most serious calculators use the same Mifflin-St Jeor equation ours does. The split is where sites differ: many use flat percentage presets, and 30 to 40% protein at a normal day's calories works out near 2.6 to 3.5 g per kg, well above the 2.2 research ceiling. Ours sets protein from your body weight, goal and training instead, the way sports nutrition research recommends, and prints every rule on this page so you can check any number by hand.
How fast should I lose weight?
The NHS advises a gradual 0.5 to 1 kg a week, which is why our pace options stop at 1. Slower paces are easier to stick to and keep more muscle, especially with enough protein. And if the maths ever pushes your calories below a safe floor, 1500 for men and 1200 for women, we hold it there and say so.
Do I need low carb to lose weight?
No. The calorie deficit does the losing, and studies comparing low-carb and low-fat diets at matched calories and protein find similar results. Pick the balance you can stick to, which is exactly why carbs fill the flexible space in this split.
Do I have to hit these numbers exactly?
No, they're targets, not a test. Within about 5 to 10 grams of each is excellent, and protein is the one to prioritise. Watch your weight trend for two to three weeks and adjust calories before touching the split.
Should everyone count macros?
It's a tool, not a requirement, and plenty of people do brilliantly just watching calories and protein. If tracking ever starts to feel obsessive or stressful around food, step back and speak to your GP, that matters more than any target on this page.
Why can I trust this calculator?
The assumptions are stated on the page, protein by body weight from published sports nutrition ranges, fat at 25% of calories, carbs as the remainder, on top of the Mifflin-St Jeor equation our TDEE calculator uses. The working is simple enough to check by hand, nothing you type is saved, and there are no ads or diet plans paying for a particular answer.
This calculator is for general information only. It isn't medical advice, a diagnosis or a treatment plan, and Biofaze isn't a healthcare provider or a medical device. Speak to your GP or another qualified health professional before acting on these numbers, especially if you're pregnant, under 18 or managing a health condition.
Protein targets scale with goal and activity inside published sports nutrition ranges, capped at 2.2 g per kg, and the calorie maths uses the Mifflin-St Jeor equation. Loss paces are capped at 1 kg a week in line with NHS guidance. Guidance last checked July 2026.