Macro Calculator UK — Protein, Carbs & Fat

Understanding Macronutrients

Protein provides 4 calories per gram and is essential for building and repairing muscle tissue, producing enzymes and hormones and supporting immune function. Good sources include meat, fish, eggs, dairy, legumes and soy products. Carbohydrates also provide 4 calories per gram and are the body’s preferred energy source, particularly during moderate to high-intensity exercise. Whole grains, fruits, vegetables and legumes are nutrient-dense carbohydrate sources. Fat provides 9 calories per gram and is vital for hormone production, nutrient absorption and brain function. Healthy fat sources include olive oil, nuts, seeds, avocados and oily fish.

The NHS recommends that the average adult diet comprises approximately 50 per cent carbohydrates, 20 per cent protein and 30 per cent fat. However, optimal macro ratios vary depending on individual goals. People aiming to build muscle typically benefit from higher protein intake, while endurance athletes may prioritise carbohydrates. The key is finding a balance that supports your specific objectives while being sustainable long-term.

Setting Your Macro Targets

For fat loss while preserving muscle, a common evidence-based approach is to set protein at 2 to 2.4 grams per kilogram of body weight, fat at 0.8 to 1.2 grams per kilogram, and fill the remaining calories with carbohydrates. This relatively high protein intake supports muscle retention during a calorie deficit and increases satiety, making the diet easier to adhere to. For muscle gain, protein can be set at 1.6 to 2.2 grams per kilogram, with carbohydrates making up a larger proportion to fuel training.

Tracking macros does not mean you must eat the same boring meals every day. Once you understand the macronutrient content of common foods, you can build varied, enjoyable meals that hit your targets. Most tracking apps have large databases that make logging straightforward. The precision required depends on your goals; serious athletes may track to the gram, while someone simply wanting a healthier diet might benefit from just being broadly aware of their protein intake.

Practical Macro Tracking Tips

Start by focusing on protein, as it is the macronutrient most people struggle to consume enough of. Include a protein source at every meal and snack. Once protein is dialled in, adjust carbohydrates and fats to fit your remaining calorie budget and personal preferences. Some people feel and perform better on higher carbohydrates, while others prefer higher fat. Neither approach is inherently superior; consistency and overall calorie balance matter more than the exact macro split for most health and body composition goals.

Calculate your daily energy needs first using our TDEE calculator, or estimate body composition with the body fat calculator. For balanced diet guidance, visit NHS Eat Well.