Toolkit Shelf

Health Calculators

Macro Calculator

Use this macro calculator to convert a calorie target and macro split into grams of protein, carbs, and fat.

Reviewed May 25, 2026EstimateFormula shown

Live calculator

Macro calculator

Protein165 g

Protein calories divided by 4 calories per gram.

Carbs and fat220 g carbs

73 g fat. Fat uses 9 calories per gram.

Macro split100%

Aim for 100% total when using macro percentages.

Formula

Macro gram formulas

Protein grams = protein calories / 4; carb grams = carb calories / 4; fat grams = fat calories / 9

Protein and carbohydrates use about 4 calories per gram. Fat uses about 9 calories per gram.

How to use

Steps

  1. Enter a daily calorie target.
  2. Enter protein, carbohydrate, and fat percentages.
  3. Check that the percentages total about 100%.
  4. Use grams as a planning estimate, not medical nutrition advice.

Example

Sample calculation

Calories2,200/day
Macro split30/40/30
Protein165 g/day

Calculator use

Best for

  • Quick macro grams from daily calories, protein percent and carb percent.
  • Wellness, nutrition, pregnancy, or fitness planning when a rough estimate is enough.
  • Scenario comparisons before changing calorie, macro, or body-measurement assumptions.
  • Planning alongside professional medical or nutrition advice, not as a diagnosis.

Before relying on it

Check first

  • Entering daily calories, protein percent and carb percent from different time periods or scenarios.
  • Treating a calculator result as medical advice or a diagnosis.
  • Using stale body, activity, pregnancy, or nutrition inputs when your situation has changed.
  • Ignoring context such as age, medication, training status, medical history, or professional guidance.

Benchmarks

How to read the result

The calculator is a decision aid, not a fixed rule. Use the output to compare scenarios and document your assumptions.

Protein4 cal/g

Commonly estimated at 4 calories per gram.

Carbs4 cal/g

Commonly estimated at 4 calories per gram.

Fat9 cal/g

Fat is more calorie-dense, so grams are lower for the same calorie share.

Calculator accuracy

Methodology and assumptions

The formula, inputs, example, and limitations are shown so the result is checkable, not just a number in a box.

Formula

Protein grams = protein calories / 4; carb grams = carb calories / 4; fat grams = fat calories / 9

Inputs used

Daily calories, Protein percent, Carb percent, Fat percent

Limitations

Results are estimates for quick planning and should be checked before important financial, legal, tax, health, or business decisions.

Last reviewed

May 25, 2026

Cite this page

Toolkit Shelf. Macro Calculator. Retrieved May 25, 2026, from https://toolkitshelf.com/tools/macro-calculator

FAQ

Common questions

How do I calculate macros?

Split calories into protein, carbs, and fat, then divide by calories per gram for each macro.

Should macro percentages add to 100%?

Yes. The split should generally add to 100% of calories.

Is this medical nutrition advice?

No. It is a planning estimate. Use professional guidance for medical or disease-specific nutrition needs.