Macro Calculator for Keto Diet — Fat Protein Carb Breakdown

Standard Keto Ratios

The ketogenic diet is a very low-carbohydrate, high-fat eating pattern designed to shift the body from glucose-based to ketone-based metabolism, a state called nutritional ketosis. The standard macronutrient distribution by calories is 70 to 75 percent fat, 20 to 25 percent protein, and 5 to 10 percent carbohydrate — often expressed as 70/25/5 or 75/20/5. In absolute carbohydrate terms this translates to roughly 20 to 50 grams of net carbohydrate per day, though the exact threshold for ketosis varies by individual and ranges from 20 g to 50 g for most adults. Fat becomes the primary fuel source, protein is kept moderate (too much protein can be converted to glucose through gluconeogenesis and may slow ketosis), and carbohydrate is the most strictly limited macro.

Net Carbs vs. Total Carbs

On keto, the relevant measurement is net carbohydrate, not total carbohydrate. Net carbs are calculated as total carbohydrates minus dietary fiber and, in some frameworks, minus sugar alcohols (such as erythritol and allulose) which have minimal metabolic impact. Fiber passes through the digestive system largely unabsorbed and does not raise blood glucose or kick you out of ketosis. For example, 100 g of broccoli contains about 7 g of total carbohydrate but only about 4 g of net carbohydrate after subtracting 3 g of fiber. Most keto trackers and apps report net carbs by default. Set your daily target at 20 to 50 g of net carbs, and keep total carbohydrate intake below 50 g to reliably enter and maintain ketosis. Track all foods using a reliable database and weigh raw foods in the early stages to calibrate portion sizes.

Protein Considerations

Protein on keto is moderate, not high in percentage terms, but adequate in absolute grams. A typical target is 1.2 to 1.7 g/kg of body weight per day — lower than the 1.6 to 2.2 g/kg/day range used in standard high-protein diets. The reason: excessive protein can be converted to glucose through gluconeogenesis, potentially slowing ketosis and increasing the caloric contribution of protein at the expense of fat. For a 75 kg adult, this means roughly 90 to 125 g of protein per day, which is sufficient to preserve muscle — especially when combined with resistance training — without displacing fat as the primary calorie source. Push toward the upper end of the range if you resistance train regularly or are trying to preserve muscle during fat loss.

Fat Quality

• Unsaturated fats: Olive oil, avocados, nuts, seeds, and fatty fish provide monounsaturated and omega-3 fats that support heart health and inflammation markers. Prioritize these as the foundation of fat intake.
• Saturated fats: Butter, coconut oil, fatty red meat, and full-fat dairy contribute saturated fat. Keep saturated fat under 10 percent of total calories, consistent with mainstream dietary guidance — this is easier on keto than most diets because total fat is already high.
• Trans fats: Avoid entirely. Found in processed foods, fried foods, and some baked goods.
• Omega-3 to omega-6 ratio: Modern diets are often skewed toward omega-6. Supplement with fish oil or eat fatty fish 2 to 3 times per week to support the ratio.

Transition Period

The transition into ketosis — often called "keto flu" — typically lasts 3 to 10 days and is caused by rapid water and electrolyte loss as glycogen stores deplete. Common symptoms include fatigue, headache, brain fog, nausea, and constipation. To ease the transition, increase electrolyte intake (sodium 3000 to 5000 mg/day, potassium 2000 to 3500 mg/day, magnesium 300 to 400 mg/day), drink plenty of water, and eat fat freely to match appetite. Most people adapt fully within 2 weeks; full metabolic adaptation (improved fat oxidation and ketone utilization) takes 4 to 8 weeks. Test ketosis with blood ketone meters (most accurate, target 0.5 to 3.0 mmol/L beta-hydroxybutyrate), urine strips (inexpensive but inaccurate after adaptation), or breath meters. Blood ketones are the most reliable non-lab measure.