Split your daily calories into protein, carbs, and fat based on your goal
This calculator provides general nutritional guidance only. It is not a substitute for professional dietary advice. Consult a registered dietitian or your GP before making significant changes to your diet, especially if you have any medical conditions.
Macronutrients -- protein, carbohydrates, and fat -- are the three main categories of nutrients that provide your body with energy. The ratio in which you consume these macros has a significant impact on your body composition, energy levels, athletic performance, and overall health. A macro split calculator helps you determine how many grams of each macronutrient to eat based on your total daily calorie intake and your specific goal. Different goals require different macro ratios. A standard maintenance split of 30% protein, 40% carbohydrates, and 30% fat works well for most people looking to maintain their current weight and support general health. Those aiming for muscle gain benefit from higher carbohydrate and protein intake to fuel workouts and support muscle protein synthesis. Fat loss protocols typically increase the protein ratio to preserve lean muscle during a calorie deficit, while ketogenic diets drastically reduce carbohydrates to shift the body's primary fuel source to fat. Understanding your macro split is more practical than simply counting calories because it tells you what to eat, not just how much. Two people eating the same number of calories can have very different body composition outcomes depending on their macro ratios. The NHS recommends that adults get their energy from a balanced mix of macronutrients, and this calculator helps you find the right balance for your individual needs and fitness objectives.
To calculate your ideal macro split: 1. Enter your daily calorie target. If you do not know your target, use our TDEE calculator first to estimate your Total Daily Energy Expenditure, then adjust based on whether you want to maintain, lose, or gain weight. 2. Select your goal. Each goal uses a different protein/carbs/fat percentage split: - Maintenance: 30/40/30 -- balanced for general health - Muscle Gain: 35/45/20 -- higher carbs and protein for training - Fat Loss: 40/30/30 -- higher protein to preserve muscle - Keto: 25/5/70 -- very low carb, high fat for ketosis - High Protein: 45/30/25 -- maximum protein for advanced athletes 3. Enter your body weight in kilograms. This is used to calculate your protein-per-kilogram ratio, which is a key metric for athletes and anyone tracking protein intake. 4. Review your results. The calculator shows grams of each macronutrient, their calorie contribution, and a pie chart visualising the split. Pay particular attention to the protein-per-kg figure and compare it to recommended ranges for your activity level.
The macro split calculation converts percentage-based ratios into grams using the caloric density of each macronutrient: - Protein: 4 calories per gram - Carbohydrates: 4 calories per gram - Fat: 9 calories per gram For a 2,000 calorie maintenance diet (30/40/30 split): - Protein: 2,000 x 0.30 = 600 calories / 4 = 150g - Carbohydrates: 2,000 x 0.40 = 800 calories / 4 = 200g - Fat: 2,000 x 0.30 = 600 calories / 9 = 67g The protein-per-kilogram figure is calculated by dividing total protein grams by body weight. For a 70kg person eating 150g of protein, this is 150 / 70 = 2.1 g/kg. The International Society of Sports Nutrition recommends 1.4-2.0 g/kg for most exercising individuals, and up to 3.1 g/kg for lean athletes during aggressive fat loss phases. Note that fat has more than twice the caloric density of protein and carbs, which is why fat grams always appear lower than you might expect when looking at the percentage split.
These macro ratios are starting points. Individual needs vary based on age, sex, body composition, training volume, and medical history. The keto split in particular should be approached with caution -- the NHS does not specifically recommend ketogenic diets, and they may not be suitable for people with type 1 diabetes, liver or kidney conditions, or a history of eating disorders. If you are unsure which split is right for you, consult a registered dietitian who can provide personalised guidance based on your full health profile.