Calories decide whether weight moves. Macros decide what that weight is made of, and whether the day is possible to actually eat. This splits a calorie budget into the three numbers a plan is written in.
Calculate your macros
Protein126g per day
Fat61g per day
Carbs287g per day
What the numbers mean
The split runs in a fixed order, because only one of the three can be the leftover:
- Protein is set from bodyweight, not from calories. It is the macro that protects muscle in a deficit, so it is decided first and held.
- Fat takes a share of the calories. Below about a fifth of intake, most people start to feel it.
- Carbs are whatever calories are left after those two. They are the flexible one, which is exactly why they go last.
Push protein and fat high enough and together they use the whole budget, leaving nothing for carbs. The calculator says so rather than showing a bare zero, because that result is a contradiction in the inputs, not an answer.
The formula, in words
Protein grams are protein-per-kilogram times bodyweight. Fat grams are the fat share of the calories divided by nine. Carb grams are the calories left over, divided by four. Four calories per gram of protein and carbs, nine per gram of fat, are the standard Atwater factors.
The defaults - 1.8 grams of protein per kilogram, a quarter of calories from fat - are the same starting values Koach itself uses when it builds a client's targets.
How a coach uses it in Koach
This is the arithmetic Koach runs when a client sets a goal: it estimates their BMR, applies the goal, then splits the result exactly this way. The calculator on this page and the app share the same code, so a plan you size here and a plan Koach sizes cannot disagree.
In the app you enter the macro targets and Koach derives the calories from them, never the other way round - see Create a nutrition plan, then Build out your meals to fill the day with food that adds up to them.