Macronutrient Calculator – Protein, Carbs & Fat Split


1Your Calorie Target

2Goal & Diet Style


Your Results
Protein
grams / day

Carbs
grams / day

Fat
grams / day

Understanding This Calculator

Macronutrients — protein, carbohydrates, and fat — each supply calories at a fixed rate (protein and carbs: 4 kcal/g; fat: 9 kcal/g). Once you know your total daily calorie target, splitting it into a macro ratio lets you hit specific body-composition or performance goals rather than just tracking total intake.

There’s no single ‘correct’ split — a balanced ratio suits general health, low-carb approaches suit some metabolic goals, and higher protein supports muscle retention during a calorie deficit.

Grams = (calories × ratio) ÷ (4 for protein/carbs, 9 for fat)
  • calories your total daily calorie target
  • ratio % allocated to each macro by goal
Macro split by diet style
Style Protein Carbs Fat
Balanced 30% 40% 30%
Low-carb 35% 20% 45%
High-protein 40% 35% 25%

Frequently Asked Questions

Why does fat use 9 kcal/g instead of 4?

Fat is more energy-dense than protein or carbohydrate — each gram yields roughly 9 kilocalories when metabolized, compared to 4 for the other two macros.

How much protein do I actually need?

General guidance is 0.7-1g per pound of bodyweight for active individuals, more during a cut to preserve muscle. This calculator’s percentages translate to reasonable gram targets across most calorie levels.