What macronutrients are
Macronutrients — protein, carbohydrate and fat — are the three nutrients that supply energy. Protein and carbohydrate each provide about 4 calories per gram; fat provides 9. A macro split describes what share of your calories comes from each, and translating that split into grams gives you a concrete target to hit through the day. Calories decide whether you lose, hold or gain weight; macros shape body composition, energy, satiety and performance within that calorie budget. This calculator does the arithmetic so you can plan meals around real gram targets.
Protein comes first
Of the three, protein is the one to anchor. It preserves muscle in a calorie deficit, is the most filling per calorie, and has the highest thermic effect, meaning your body burns more digesting it. Common guidance is 1.6–2.2 grams of protein per kilogram of body weight for people who train, which often lands near the higher-protein splits here. If a split gives you less protein than that, lean toward the high-protein option. Carbohydrate then fuels training and fat covers hormones and the rest of your energy.
Choosing a split
There is no single best split — the right one fits your goal and preferences. Balanced (30/40/30) suits most people and general training. Higher-protein splits help when cutting or building muscle. Low-carb and keto shift energy toward fat and can aid appetite control for some, though they are not required for fat loss; total calories still decide that. Pick a split you can stick to, keep protein adequate, and adjust carbs and fat to taste and training. Consistency beats the perfect ratio.
Making macros work in practice
Weigh and log food for a week or two to learn portion sizes, prioritise whole foods, and aim to hit protein first with carbs and fat filling the rest. You do not need to hit every gram exactly — within about 5–10 grams is fine. Use the TDEE calculator to set the calorie target this split divides up, and revisit both as your weight and goals change. These tools use standard, published formulas and the figures you enter. They are estimates for general fitness and planning, not a medical assessment — check with a doctor or dietitian before making health decisions.
Frequently asked questions
How are macros calculated from calories?
Protein and carbs are 4 calories per gram, fat is 9. The calculator multiplies your calories by each macro's percentage, then divides by 4 or 9 to get grams.
How much protein should I eat?
For people who train, about 1.6–2.2 grams per kilogram of body weight per day preserves and builds muscle. Choose a split that gets you into that range.
Which macro split is best for fat loss?
Any split works if calories are in a deficit and protein is high enough. Higher-protein splits help preserve muscle and control hunger while cutting.
Do I have to hit my macros exactly?
No. Getting within roughly 5–10 grams of each target, and hitting protein consistently, is plenty for good results. Perfection is not required.