Low Carb Macro Calculator

On this page low-carb is a reduced-carb 40/20/40 split: carbohydrate takes 20% of your calories, which works out to roughly 100 grams at a 2,000-calorie total. That is well below a balanced diet, where carbohydrate often takes 40% or more, but it is not the same as keto. Keto pushes carbohydrate far lower — to around 5% of calories — so that fat becomes the body’s main fuel. The reduced-carb split here simply trims carbohydrate and rebalances the freed calories toward protein and fat, keeping carbohydrate in the diet rather than near-eliminating it. Set the split with the Macro Calculator, then check the protein grams against your body weight with the Protein Intake Calculator.

Take a 2,000-calorie day on the 40/20/40 split. Protein takes 40%, which is 800 calories, and at 4 calories per gram that is 200 grams. Carbohydrate takes 20%, or 400 calories, again at 4 calories per gram — 100 grams. Fat takes the last 40%, 800 calories, but fat carries 9 calories in every gram, so it comes to about 89 grams. Add the calories back — 800 plus 400 plus 800 — and you return to 2,000, the check that the split is complete. Change the calorie total and every gram figure scales with it.

A common practical note when reducing carbohydrate is that electrolyte support is recommended, as the body tends to shed water and salts in the early days of a lower-carb diet. That is mentioned here as a widely repeated point people plan around, not as a medical claim. If your low-carb total is meant to create a deficit for weight loss, the Calorie Deficit Calculator sets that number; bring it here to split into grams. These figures are general estimates for healthy adults, not medical advice.