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Health calculator

Macro Calculator

Convert a calorie target and macronutrient percentages into grams of protein, carbohydrate and fat.

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Complete guide

Macro calculator with grams, calories and AMDR context

Enter daily calories plus protein and fat percentages. Carbohydrate fills the remainder. Calculator24 converts each share to calories and grams and graphs the complete 100% energy distribution.

Editorial checkEnergy conversion and adult AMDR ranges checked against NIH and National Academies references.Updated September 10, 2026
Turn energy shares into gramsChoose percentages that total 100%, assign calories to each macronutrient, then divide by 4 or 9 kcal per gram.1Percentages2Macro calories3Grams/day
Turn energy shares into gramsChoose percentages that total 100%, assign calories to each macronutrient, then divide by 4 or 9 kcal per gram.

What macronutrients are

Protein, carbohydrate and fat provide most food energy. A macro split describes their percentage of total calories; it does not describe fiber, vitamins, minerals or food quality.

Calories per gram

Protein and carbohydrate use 4 kcal per gram in this calculation. Fat uses 9 kcal per gram. Multiplying total calories by a percentage gives macro calories before conversion to grams.

protein g=calories×protein%÷4carb g=calories×carb%÷4fat g=calories×fat%÷9

Worked example

For 2,200 kcal at 25% protein and 30% fat, carbohydrate is 45%. Protein receives 550 kcal or 137.5 g; fat receives 660 kcal or 73.3 g; carbohydrate receives 990 kcal or 247.5 g.

AMDR reference ranges

National Academies adult AMDRs provide broad energy ranges: carbohydrate 45–65%, fat 20–35% and protein 10–35%. The calculator flags whether each entered share falls inside those general ranges.

Why carbohydrate is the remainder

Using the remainder guarantees the three shares total exactly 100%. Protein plus fat must stay below 100; otherwise no energy remains for carbohydrate.

From grams to foods

A grams target is not a menu. Food choices also affect fiber, essential fatty acids, amino acids, micronutrients, sodium and dietary pattern. Individual guidance may differ from a general AMDR.

Adult AMDR and energy conversion

General population ranges and factors used by this calculator.
MacroAMDREnergy factor
Protein10–35%4 kcal/g
Carbohydrate45–65%4 kcal/g
Fat20–35%9 kcal/g

Frequently asked questions

How are macro grams calculated?

Assign calories by percentage, then divide protein and carbohydrate by 4 kcal/g and fat by 9 kcal/g.

Why is carbohydrate automatic?

It receives the percentage remaining after protein and fat so the total stays at 100%.

What is AMDR?

It is the Acceptable Macronutrient Distribution Range expressed as a percentage of energy.

Does this create a meal plan?

No. It only divides a calorie target among macronutrients.

Are macro needs the same for everyone?

No. Age, health, pregnancy, training and clinical needs can change appropriate intake.

What to keep in mind

This calculator divides energy; it does not determine an individualized nutrient requirement or meal plan. Medical conditions, pregnancy, sport and age can change appropriate targets.

Results display up to 8 decimal places; exported numbers preserve calculation precision. This is a calculation summary, not an official certificate.

Sources and references

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