Estimate daily calories from the Mifflin-St Jeor equation and split them into keto fat, protein and carbohydrate grams.
Result
How to use this tool
Use kg, cm and years; these drive the BMR equation.
The equation differs by sex and scales with how active the day is.
70% fat, 25% protein and 5% carbohydrate, shown as grams per day.
Calories here maintain weight; a deficit or surplus changes the grams proportionally.
Formula & worked example
An 80 kg, 180 cm, 30-year-old man has a BMR of 1,780 kcal; moderately active (x1.55) that is 2,759 kcal/day, split as about 215 g fat, 172 g protein and 34 g carbohydrate.
Limitations — read this before you rely on it
Estimates from a standard equation and a standard keto split, not a personalised diet plan. Very-low-carbohydrate diets need clinical input for several conditions. This tool is for education only and is not medical advice. Talk to a clinician about any result that worries you, and never change treatment because of a calculator result.
Frequently asked questions
A very-low-carbohydrate, high-fat diet, typically around 70% fat, 20-25% protein and 5-10% carbohydrate of calories.
With very little carbohydrate, the liver produces ketones from fat, which become a major fuel.
This tool uses 25% of calories; athletes and some medical conditions need a different, clinician-set target.
No. The Mifflin-St Jeor equation is an estimate; real expenditure varies with body composition and daily activity.
It is not suitable for everyone, including in pregnancy, type 1 diabetes and certain metabolic disorders; check with a clinician first.