Macro Calculator
Knowing your macros — protein, carbohydrates, and fat — is the foundation of any physique goal. Whether you are cutting, maintaining, or building, the ratio and quantity of these three nutrients directly shapes your body composition. This calculator estimates your daily macro targets based on your stats, activity level, and goal, using the Mifflin–St Jeor equation to calculate your basal metabolic rate and applying your activity and goal modifiers to give you a practical, personalised starting point.
How to Track Macros
The most straightforward method is to use a food-logging app such as MyFitnessPal or Cronometer, weighing your food on a kitchen scale for accuracy. Log everything you eat, checking that your daily protein, carbohydrate, and fat totals land within a reasonable range of your targets — within 5–10% is considered on track.
For those who prefer a less granular approach, hand-portion methods work reasonably well. A palm-sized portion approximates a protein serving, a fist approximates a carbohydrate serving, and a thumb represents a fat serving. It lacks the precision of weighing but builds strong nutritional awareness over time.
The most important principle is consistency. Tracking 80% of the time consistently will outperform perfect tracking for a week followed by abandonment. Start with protein — the most critical macro for body composition — and work backwards from there.
Where macro tracking meets its limit is in measuring the visual results of your nutrition. That is where SKŌR comes in. SKŌR's Body SKŌR uses AI to analyse changes in your physique from photos, giving you an objective read on how your nutrition strategy is translating to your appearance — the metric that most people actually care about.
What Are Macros? A Quick Guide
Macronutrients are the three primary classes of nutrients your body uses for energy and structural functions. Every food you eat is made up of some combination of these three.
Protein (4 kcal per gram) is the building block of muscle tissue. It also supports immune function, hormone production, and enzyme activity. During a calorie deficit, adequate protein is the single most important factor in preserving lean muscle mass.
Carbohydrates (4 kcal per gram) are your body's preferred fuel source, particularly for high-intensity exercise. They are stored in the muscles and liver as glycogen, which is rapidly mobilised during training. Adequate carbohydrate intake supports performance, mood, and thyroid function.
Fat (9 kcal per gram) is essential for hormone production — including testosterone and oestrogen — fat-soluble vitamin absorption (A, D, E, K), brain health, and joint lubrication. Fat should never be eliminated entirely; a floor of around 0.7g per kg of bodyweight is considered the minimum for healthy hormonal function.
The ratio between these three macros is what determines whether a given calorie intake drives fat loss, muscle gain, or maintenance — which is why macros matter more than calories alone when body composition is the goal.
How Much Protein Do I Need?
The evidence-based recommendation for physically active individuals is 1.6–2.2g of protein per kilogram of bodyweight per day. The lower end of this range — around 1.6g/kg — is sufficient for most people in a calorie surplus or maintenance phase. The upper end — 2.0–2.2g/kg — is more appropriate during a calorie deficit, where the risk of muscle loss is higher and extra protein provides a buffer.
This calculator uses 2.0g/kg as its default, which sits at the upper-middle of the recommended range and is appropriate for most people who train regularly. If you are considerably overweight, it is more accurate to base your protein target on your target bodyweight rather than your current bodyweight.
Spreading protein intake across three to four meals throughout the day maximises muscle protein synthesis, as each serving stimulates a new anabolic response. A target of 30–50g of protein per meal is a practical guideline for most people.
Frequently Asked Questions
What is a macro calculator?
A macro calculator estimates your daily targets for the three macronutrients — protein, carbohydrates, and fat — based on your body stats, activity level, and goal. It uses your BMR (basal metabolic rate) and TDEE (total daily energy expenditure) to work out how many calories you need, then divides those calories into macro targets aligned with your physique goal.
How do I calculate my macros for weight loss?
To calculate macros for weight loss, first determine your TDEE using your age, height, weight, and activity level. Then apply a calorie deficit — typically 15–25% below maintenance. Prioritise protein at around 2g per kg of bodyweight to preserve muscle, set fat at roughly 25% of total calories, and fill the remainder with carbohydrates. This calculator handles all of that automatically when you select a "cut" goal.
What macro ratio is best for building muscle?
For muscle building, a common starting point is 30–35% protein, 40–50% carbohydrates, and 20–25% fat. Prioritising protein at 1.6–2.2g per kg of bodyweight supports muscle protein synthesis, while sufficient carbohydrates fuel training performance and recovery. A modest calorie surplus of 10–20% above maintenance provides the energy needed for growth without excessive fat gain.
Should I track macros or just calories?
Tracking macros gives you more control than tracking calories alone. Two people eating the same number of calories can have very different body composition outcomes depending on how much protein they consume. If your goal is body recomposition — losing fat while maintaining or gaining muscle — tracking macros is significantly more effective than counting calories alone. Calories determine your weight trajectory; macros determine what you are made of.
How much protein do I need per day?
Current evidence supports a range of 1.6–2.2g of protein per kg of bodyweight per day for individuals who train regularly. For a lean 75 kg person, that equates to 120–165g of protein daily. Aim for the higher end if you are in a calorie deficit or new to resistance training to maximise muscle retention and stimulate adaptation.
What happens if I eat too much protein?
Excess protein above your body's needs is either oxidised for energy or — in significant surpluses — stored as fat. For healthy individuals with functioning kidneys, high protein intakes in the range of 2–3g/kg are generally considered safe. The main concern is displacement: if protein takes up too large a share of your calories, carbohydrate intake may drop too low to sustain training performance, and energy levels can suffer as a result.
How do macros change on rest days?
Many people choose to reduce carbohydrate intake on rest days, since carbohydrates primarily fuel physical activity. A common approach is to keep protein constant, reduce carbs by 20–30%, and slightly increase fats to compensate. This is known as carb cycling and can help manage overall calorie intake while keeping protein high for recovery. It is not necessary for beginners but can be a useful tool once you have a solid baseline in place.
Is macro tracking necessary for beginners?
Macro tracking is not strictly necessary for beginners, but it is one of the most educational habits you can build early. Even tracking for just 4–6 weeks gives you a lasting intuition for the protein, carbohydrate, and fat content of the foods you eat regularly. Beginners who track macros tend to make faster progress towards body composition goals than those who rely on rough estimates — and they are far less likely to make the classic mistake of significantly under-eating protein.
Track the Visual Results of Your Nutrition
SKŌR uses AI to score your face and body, so you can see exactly how your macro strategy is changing your physique — not just on the scale, but in the mirror.
