Calorie Macro Calculator

Translate grams of macros into total calorie distributions or split target calories into macro grams.

Enter Macro Grams

Protein

Carbohydrates

Fat

Alcohol

Calculate Net Carbs (Deduct Fiber & Sugar Alcohols)

Total Energy Value

2030 kcal

Protein:30%

Carbs:39%

Fat:31%

Alcohol:0%

How Macronutrient Calculations Work

Each of the core macronutrients contains a specific quantity of energy per gram:Protein (4 kcal/g), Carbohydrates (4 kcal/g),Fat (9 kcal/g), and Alcohol (7 kcal/g).

Under Net Carbohydrate guidelines, dietary fiber (2 kcal/g) and sugar alcohols (typically ~1.6 kcal/g) are subtracted from total carbohydrates, allowing ketogenic or low-carb diets to isolate the net carbs that impact blood glucose.

Built and maintained by Meet Shah · Last updated 1 August 2026

What this tool is used for

Working out total calories from macronutrient grams.
Checking a label's stated calories against its macros.
Comparing two meals on macro split rather than calories alone.
Working out how much of a day's energy comes from each macro.
Converting a macro target into gram amounts.

Frequently Asked Questions

Where do the 4, 4 and 9 come from?: The Atwater general factors: 4 kcal per gram of protein and of carbohydrate, 9 for fat. They are averages of measured heats of combustion less digestive losses, which is why a label's stated calories rarely match the arithmetic exactly.
Why is alcohol counted at 7?: Ethanol yields about 7 kcal/g, between carbohydrate and fat, and it is not a macronutrient so most labels omit it. A 175 ml glass of 13% wine holds roughly 18 g of alcohol — about 126 kcal before any residual sugar is counted.
What are net carbs?: Total carbohydrate minus fibre and sugar alcohols. Switching net carbs on stops counting those at 4 kcal/g and applies 2 kcal/g to fibre and 1.6 to sugar alcohols, because they are only partly absorbed. EU labelling law uses 2 for fibre and 2.4 for polyols.
Do all sugar alcohols have the same calories?: No — 1.6 kcal/g is a blended average. Erythritol is close to zero because it is absorbed and excreted unchanged; xylitol is about 2.4 and maltitol 2.1–3.0. Maltitol also raises blood glucose far more than the other two.
Which macro split should I choose?: The presets are conventions, not prescriptions: 40/30/30 (the Zone ratio), 25/40/35 for higher protein and satiety, 20/35/45 low-carb, 5/20/75 ketogenic. Only the ketogenic split is defined by a physiological target — keeping carbohydrate low enough to sustain ketosis.
How accurate are the equations behind this?: Estimates within roughly 10% for most people, and further out for anyone very lean, very heavy or highly trained. They predict a population average, so the practical method is to start from the number and adjust from real results.

Common errors and gotchas

Using four calories per gram for fat, which is nine.
Forgetting alcohol contributes about seven calories per gram.
Assuming label calories match the macro arithmetic exactly, since fibre and rounding rules differ.
Treating the calculation as a nutritional plan rather than arithmetic.
Ignoring that fibre is often counted differently between jurisdictions.