Ketogenic Diet Macro Calculator

The ketogenic diet fundamentally shifts the body's primary fuel source from glucose to ketone bodies — molecules produced in the liver from fat when carbohydrate intake is sufficiently low. For most people, this threshold is roughly 20–50g of net carbohydrates per day. Below this level, glycogen stores are depleted, insulin levels fall, and fat mobilization increases — both from dietary fat and stored body fat.

Macro ratios on keto are roughly 70% fat, 25% protein, and 5% carbohydrates. Protein targets matter: too little leads to muscle loss (especially in a caloric deficit); too much can stimulate gluconeogenesis, where protein is converted to glucose and potentially disrupts ketosis. The 25% protein target provides approximately 0.7–0.9g per pound of body weight for most individuals, which is sufficient for muscle preservation.

The initial adaptation period — often called "keto flu" — lasts 3–7 days and involves fatigue, headaches, and brain fog as the brain switches from relying on glucose to ketones. Aggressive electrolyte supplementation (particularly sodium and potassium) dramatically reduces these symptoms. After full adaptation (4–8 weeks), most people report stable energy, reduced hunger, and improved mental clarity — explaining keto's strong adherence rates among its proponents.