Nutrition & Metabolism
Macro Calculator
Turn your daily calorie target into a personalised protein, carb and fat breakdown.
Macro Calculator Tool
Why macros matter beyond calorie counting
Calories determine whether you gain, lose or maintain weight, but the mix of protein, carbohydrate and fat you eat those calories from — your 'macros' — shapes how you feel, perform and hold onto muscle along the way. Two people eating the same 2,000 calories can have very different results if one eats mostly protein and vegetables while the other eats mostly refined carbs and fried food. This calculator starts with your estimated calorie needs, using the same Mifflin-St Jeor formula as our Calorie Calculator, and splits that number into grams of each macronutrient.
How the splits are built
We offer three common diet styles: a balanced split (roughly 30% protein, 40% carbohydrate, 30% fat), a lower-carb split that shifts more calories toward protein and fat, and a higher-protein split favoured by people focused on muscle retention during a calorie deficit. Each gram of protein and carbohydrate provides about 4 calories, while each gram of fat provides about 9 calories, which is how we convert your percentage split into actual grams to track.
Matching macros to your goal
If your priority is preserving muscle while losing fat, a higher-protein split tends to perform well in research, since protein has a stronger effect on satiety and muscle protein synthesis than the other macronutrients. If you're simply aiming to eat a well-rounded, sustainable diet without a specific performance goal, the balanced split is a sensible, flexible default. Low-carb approaches can suit some people's preferences and appetite control, but they aren't inherently superior for fat loss once total calories and protein are matched.
Using your macro numbers day to day
Most people find it easier to hit a protein target consistently than to hit carb and fat numbers exactly — protein is the macro most worth prioritising precisely. Apps that log food can help you see how your typical meals line up with these numbers without demanding you weigh every ingredient forever. Recalculate every few weeks or after a meaningful change in weight or activity level, since your calorie needs shift as your body does.
Frequently Asked Questions
What are macros?
Macros (macronutrients) are the three nutrient groups that provide calories: protein, carbohydrate and fat. Each plays a different role in energy, muscle repair and hormone function.
Which macro split is best for fat loss?
A higher-protein split is often recommended during a calorie deficit because protein helps preserve muscle mass and supports fullness, but the 'best' split ultimately depends on what you can sustain consistently.
Do I need to hit my macros exactly every day?
No. Aim to land within a reasonable range, especially for protein, over the course of a week rather than treating daily numbers as an exact prescription.
How is this different from the calorie calculator?
The Calorie Calculator gives you a single daily calorie target. This Macro Calculator takes that same estimate and breaks it down further into grams of protein, carbs and fat based on your chosen diet style.
Can I customise the percentage split myself?
This calculator offers three common presets (balanced, low-carb, high-protein). If you have a specific ratio prescribed by a coach or dietitian, you can manually adjust the resulting gram targets to match.