Macro Calculator

What It Does

Split a daily calorie target into grams of protein, carbohydrate and fat. You can type the target in yourself or derive it from your body stats — sex, age, height, weight and activity level — and you can take one of four diet presets or set the three percentages by hand. Every result shows the grams, each macronutrient's share of the day's calories, and a fibre target of 14 g per 1 000 kcal. Protein and carbohydrate are counted at 4 kcal per gram and fat at 9.

Real-World Usage

Use it when you already know the calories you are aiming at — from a nutrition plan, a training goal or a maintenance estimate — and need the grams to weigh or log. In the body-stats mode it also answers the first question almost everyone asks: how many calories you maintain on, before any deficit or surplus. Coaches use it to turn a percentage prescription into numbers a client can track, and the same page converts a prescribed split back into calories when a plan changes.

Local Context

The four presets are built from the ranges public health bodies publish: protein 10–35 %, carbohydrate 45–65 % and fat 20–35 % of calories, with the balanced preset (25/45/30) inside all three. The fibre reference of 14 g per 1 000 kcal comes from the same guidance — 28 g a day on a 2 000 kcal diet. The energy target itself is personal: the derived figure uses the Mifflin-St Jeor equation and an activity multiplier, which is an estimate rather than a measurement. These are general educational figures — a clinical condition, pregnancy, medication or an eating disorder changes what is appropriate, and that is a conversation with a clinician, not a calculator.

Where the Limits Come From

The saturated-fat and free-sugar limits are both set at 10 % of the daily energy target, the population goal the World Health Organization sets for each of them. They are ceilings for a whole diet, not a quantity to fill, and they move with your calories: at 2 000 kcal a day they sit at 22 g of saturated fat and 50 g of free sugars. National guidelines differ in the detail — some countries recommend 5 % for free sugars — which is why the page prints the WHO reference and leaves your own market’s stricter figure to your dietitian or your food label.

How each preset is derived

Each preset is a fixed share of calories per macronutrient, not a food list. Balanced (25/45/30) stays inside the published ranges for all three macros, so it is the safest default for most people. High protein (35/35/30) takes protein to the top of its range: useful for holding on to lean mass in a deficit, harder to reach on a plant-only diet. Low carb (30/20/50) inverts the usual ratio while keeping protein high enough to protect muscle. Ketogenic (25/5/70) is the classic very-low-carbohydrate pattern, and its carbohydrate figure is net carbohydrate, so fibre is not subtracted a second time.

Trade-offs to know

The three shares always add up to 100 %, so raising one lowers another: more protein leaves less room for carbohydrate around hard training, and more fat makes a target harder to reach on a low-calorie day because fat carries 9 kcal per gram. Protein is the macro most people under-reach and the one with the best-supported floor — around 1.6 g per kilogram of body weight for anyone training. A percentage can also hide an absolute number: 25 % protein is 100 g at 1 600 kcal and 138 g at 2 200 kcal, so a plan written in percentages has to be re-read whenever the calorie target moves.

What is a macro split?

A macro split is the share of your daily calories that comes from protein, carbohydrate and fat. The three shares always add up to 100 %, and each one is converted into grams at its own energy value: 4 kcal per gram for protein and carbohydrate, 9 kcal per gram for fat.

Which preset should I choose?

Balanced (25 % protein / 45 % carbohydrate / 30 % fat) sits inside the ranges public health bodies publish for all three macros, so it suits most people. High protein takes protein to the top of its range; the low-carb and ketogenic presets cut carbohydrate further and raise fat instead.

Is a ketogenic split safe?

A ketogenic split (about 5 % carbohydrate) is a clinical-style pattern that changes how the body fuels itself. It is usually followed under supervision, is not recommended in pregnancy or with some metabolic conditions, and its carbohydrate figure counts net carbohydrate — fibre is tracked separately.

Do I need to hit the fibre target?

The fibre target is 14 g per 1 000 kcal, the reference public health guidelines use. It is a level to aim at rather than a limit: most people fall short of it, and fibre changes how filling a meal feels and how slowly carbohydrate is absorbed.