4-4-9 Rule
A quick way to estimate calories from macros: carbs (4), protein (4), fat (9) calories per gram.
Definition
The 4-4-9 rule estimates calories by multiplying grams of carbohydrate by 4, grams of protein by 4, and grams of fat by 9, then adding the totals. It’s a useful approximation for planning meals and macro targets.
Example
50g carbs (200) + 30g protein (120) + 15g fat (135) ≈ 455 calories.