Macro Calculator

Setting protein first

Protein is the macronutrient with the clearest evidence for a target, so it is set first and the others fill the remaining energy.

For general health, around 0.8 grams per kilogram of body weight is the minimum recommended intake, which is a floor for avoiding deficiency rather than an optimum.

For anyone training, losing weight, or over about sixty, the evidence supports considerably more: commonly 1.6 to 2.2 grams per kilogram. Higher intakes have not been shown to add benefit for most people, and there is no evidence of harm from high protein intake in people with healthy kidneys.

Fat, and the floor below which not to go

Dietary fat is required for absorbing fat-soluble vitamins and for hormone production, so there is a floor rather than a target.

Around 0.5 to 0.6 grams per kilogram of body weight, or roughly 20% of total energy, is a reasonable minimum. Going substantially below that for extended periods is associated with hormonal disruption, and the effect appears more pronounced in women.

Above the floor, the split between fat and carbohydrate is largely a matter of preference and adherence. Controlled studies matching protein and total energy consistently find little difference in fat loss between higher-fat and higher-carbohydrate approaches.

Carbohydrate as the remainder

With protein and fat set, carbohydrate takes whatever energy is left. That is not a demotion; it reflects that carbohydrate has the widest tolerable range.

Higher carbohydrate intake supports higher training volumes and higher intensity work, because glycogen is the fuel for anaerobic effort. Endurance and strength athletes generally do better at the higher end.

Lower carbohydrate approaches suit people who find them more satiating and easier to adhere to. Adherence is the variable that predicts outcomes in almost every dietary comparison study, which is why the best macro split is frequently the one someone will actually follow.

The arithmetic

Protein and carbohydrate provide roughly 4 calories per gram, fat roughly 9, and alcohol 7.

So a 2,000 calorie plan at 150 grams of protein and 60 grams of fat uses 600 and 540 calories respectively, leaving 860 for carbohydrate, which is 215 grams.

Rounding is fine. Hitting macros within five or ten grams is well within the noise of food labelling accuracy, which is permitted to be out by a meaningful margin in most jurisdictions, and within the day-to-day variation of the food itself.

What macros do not determine

Total energy determines weight change. Macronutrient distribution influences body composition, satiety, training performance and adherence, and it does not override energy balance.

Food quality sits outside the macro framework entirely. Two diets with identical macros, one built on whole foods and one on processed equivalents, differ in micronutrients, fibre and satiety, and the difference matters for health even where it does not show on the scale.

Micronutrients and fibre need attention separately. A plan that hits its macros precisely while providing 8 grams of fibre and no vegetables is a plan that meets its targets and is not a good diet.

One more caution about precision. Food labels are permitted to deviate from their stated values by a tolerance that is wider than most people expect, and the natural variation in whole foods is wider still: two apples of the same weight differ, and so do two cuts of the same joint. Chasing macros to the gram is therefore chasing an accuracy the underlying data does not have. Consistency in how you track matters far more than precision in what you track, because a consistent method with a consistent bias still shows you the direction of change.