Macro Calculator

How to use the macro calculator

1. Fill in the fields — they start with a worked example.
2. Read the answer, and the arithmetic shown beneath it.
3. Copy the results, or adjust the inputs to compare scenarios.

About this tool

Macronutrients carry different amounts of energy, and that is the whole calculation: protein and carbohydrate provide about 4 calories per gram, fat about 9, and alcohol 7. A gram of fat is worth more than twice a gram of protein, which is why a split that looks balanced in percentages looks very different in grams.

Two ways of setting the split are offered because they answer different questions. Percentages divide a calorie target and suit someone following a named approach. Setting protein and fat per kilogram of body weight and letting carbohydrate take the remainder is what most evidence-based guidance actually does, since protein needs scale with body size rather than with how much you happen to be eating.

The protein figures worth knowing: around 0.8 g per kilogram is the minimum to avoid deficiency, 1.2 to 1.6 is a reasonable general target, and 1.6 to 2.2 is the range that shows benefit for people training with weights. Above that the evidence flattens out. Fat below about 0.5 g per kilogram starts to interfere with hormone production and the absorption of fat-soluble vitamins, so the calculator flags it rather than letting a low-fat split run to zero.

What none of this decides is whether the calorie target itself is right, and that is the number that actually determines weight change. A macro split affects body composition, satiety and training performance at a given intake; it does not override the intake.

Common uses

• Turning a calorie target into daily gram targets.
• Setting protein by body weight rather than by percentage.
• Comparing how two splits differ in actual food terms.

Frequently asked questions

How many calories are in a gram of each macro?

About 4 in protein and carbohydrate, 9 in fat and 7 in alcohol. That difference is why percentage splits and gram splits look so unlike each other.

How much protein should I eat?

Around 0.8 g per kilogram avoids deficiency, 1.2 to 1.6 is a sensible general target, and 1.6 to 2.2 is the useful range for people training with weights. Beyond that the evidence flattens.

Do macros matter more than calories?

No. Calories determine weight change; macros affect body composition, satiety and training at a given intake. A split cannot rescue a target that is wrong.