Macro Calculator
Calculate macronutrient splits
Macro Calculator tool
Macro Calculator
Macro Calculator: key facts
- What it does
- Calculate macronutrient splits
- Category
- Health & Fitness Calculators
- Cost
- Free, with no account, sign-up, or install.
- Your data
- Runs entirely in your browser — the files and text you enter are never uploaded to a server.
- Last reviewed
- . Report an incorrect result.
About the Macro Calculator
Hitting a calorie target is only half the story — how those calories split across protein, carbohydrates, and fat shapes your results. This Macro Calculator takes your daily calorie target and a diet style and converts it into grams of each macronutrient to aim for.
People following a structured eating plan use it to translate a calorie goal into a shopping-and-cooking reality, whether they are eating balanced, cutting carbs, prioritizing protein, or going keto. Each diet preset carries its own ratio, and the tool does the calorie-to-gram math — accounting for the fact that protein and carbs carry 4 calories per gram while fat carries 9.
How to use it
- Enter your daily calorie target (use a TDEE or calorie calculator to find it).
- Choose a diet type: Balanced, Low Carb, High Protein, or Keto.
- Read the grams of protein, carbs, and fat to aim for each day.
- Note the percentage split shown alongside each macro, then Copy the targets.
Splitting calories into grams
A macro target is a calorie target divided three ways. The tool applies your chosen percentage split to the daily calorie figure, then converts each share into grams using the energy density of that macronutrient: four calories per gram for protein and for carbohydrate, nine for fat.
That asymmetry is the thing to internalise. Because fat carries more than twice the energy per gram, an equal percentage split does not produce equal gram counts — thirty percent of calories from fat is a much smaller number on the plate than thirty percent from carbohydrate. It is also why fat targets are easy to overshoot without noticing.
The percentages always total one hundred, so raising one macronutrient necessarily lowers another. There is no way to increase protein without taking the calories from carbohydrate or fat unless the overall target rises.
- On 2,000 calories at a 40/30/30 carbohydrate–protein–fat split: 200 g carbohydrate, 150 g protein, and 67 g fat.
- Shifting the same 2,000 calories to a lower-carbohydrate 25/35/40 split gives 125 g carbohydrate, 175 g protein, and 89 g fat.
- Note the fat column in both: 30% of calories is 67 g while 40% is 89 g, so a ten-point change moves fat by only 22 g — the density effect in practice.
Why use this version
- It offers four ready-made diet profiles — balanced, low-carb, high-protein, and keto — each with its split shown right in the option label.
- It correctly converts calories to grams using 4 calories per gram for protein and carbs and 9 for fat, so the gram targets are accurate.
- It shows all three macros at once with both grams and percentages, giving you a complete daily picture.
- Calculations are instant and client-side, with no account required.
Which split, and how closely to follow it
For weight change, total calories do the overwhelming majority of the work; the split mainly affects how easy the target is to stick to and how well you retain muscle. Higher protein tends to help on both counts, being the most satiating macronutrient and the one that protects lean tissue during a deficit.
Beyond that, the best split is largely the one you can sustain. Trials comparing low-fat against low-carbohydrate approaches at matched calories generally find small differences in outcome and large differences in individual adherence. Athletes in glycogen-dependent sports usually do want carbohydrate higher; someone who finds fat more satisfying will do better with it higher.
Hitting percentages precisely every day is neither necessary nor realistic — landing within a reasonable margin across a week is what matters. And micronutrients, fibre, and food quality are invisible to this calculation: three plates can match the same macros exactly while differing enormously in nutritional value. If you are managing diabetes, kidney disease, or any condition where macronutrient balance is clinically relevant, work to a dietitian's plan rather than a generic split.
Frequently Asked Questions
What are macronutrients?
Macronutrients — protein, carbohydrates, and fat — are the three nutrients that provide energy. Protein and carbs supply about 4 calories per gram and fat about 9, which is why the same calorie target yields different gram amounts depending on the split.
Which diet split should I pick?
It depends on your goal and preference. Balanced suits general health, higher protein supports muscle retention and satiety, low-carb appeals to some for fat loss, and keto pushes fat very high and carbs very low. There is no single best split — pick one you can sustain.
How do I turn calories into grams of each macro?
Multiply your calorie target by each macro's percentage, then divide by that macro's calories per gram — 4 for protein and carbs, 9 for fat. This calculator runs that math automatically for the diet style you select.
Do I need to hit my macros exactly?
Treat the numbers as targets to aim for, not strict rules. Getting reasonably close most days matters far more than perfection at every meal, and protein is usually the macro worth tracking most closely.
