Keto Macro Calculator: Fat, Protein & Net Carbs for Ketosis
Get your personalised ketogenic macro targets in seconds — daily fat, protein, and net carb goals calibrated to your body, activity level, and goal.
Most people reach ketosis at 20–30g net carbs/day. 50g is a liberal keto approach.
What Is a Ketogenic Diet?
A ketogenic (keto) diet is a very low-carbohydrate, high-fat diet that shifts the body into a metabolic state called ketosis. When carbohydrate intake is severely restricted, the liver converts fat into ketone bodies, which become the primary fuel source for the brain and body instead of glucose.
The diet was originally developed in the 1920s as a treatment for epilepsy, but has since gained widespread popularity for fat loss, metabolic health, blood sugar management, and mental clarity. The standard ketogenic diet (SKD) typically consists of 70–80% fat, 15–20% protein, and only 5% carbohydrates.
Keto Macro Breakdown
Fat
70–80% of calories
The primary fuel source on keto. Comes from sources like avocado, olive oil, nuts, butter, fatty fish, and coconut oil. Fat provides 9 kcal per gram — far more calorie-dense than protein or carbs.
Protein
15–20% of calories
Moderate protein preserves muscle and supports metabolic function. Aim for 1.5–1.8g/kg of body weight. Too little increases muscle loss; too much may impair ketosis via gluconeogenesis.
Net Carbs
20–50g per day
The most critical variable for achieving ketosis. Start at 20g for reliable ketosis. Focus on leafy greens, cruciferous vegetables, and low-carb options. Avoid grains, sugar, fruit, and starchy vegetables.
Which Net Carb Limit Is Right for You?
| Net Carb Limit | Best For | Ketosis Reliability |
|---|---|---|
| 20g/day | Beginners, therapeutic use, weight loss | Very high — suitable for almost everyone |
| 25g/day | Most people after initial adaptation | High — works for most metabolisms |
| 30g/day | Active individuals, carb cycling approach | Moderate — depends on activity and metabolism |
| 50g/day | Very active athletes, maintenance phase | Lower — may exit ketosis with low activity |
Protein on Keto: How Much Is Too Much?
Protein is a common area of confusion on keto. Gluconeogenesis — the metabolic pathway by which the body converts protein (and other substrates) into glucose — is sometimes cited as a reason to limit protein on keto. However, gluconeogenesis is primarily demand-driven, not supply-driven. Eating moderate amounts of protein does not meaningfully impair ketosis for most people.
The practical risk is eating too little protein, which accelerates muscle breakdown. Aim for 1.5–1.8g per kg of body weight as a minimum. Athletes and those doing resistance training can go up to 2.0g/kg without significantly affecting ketone production.
Frequently Asked Questions
How many net carbs do I need to stay in ketosis?
Most people reach and maintain ketosis by keeping net carbs (total carbs minus fibre) between 20–30g per day. Some metabolically flexible individuals can sustain ketosis at 30–50g, especially with regular exercise. Starting at 20g is the most reliable approach, particularly in the first 2–4 weeks. Once fat-adapted, you can experiment with slightly higher limits.
How much protein should I eat on keto?
Protein on keto should be moderate — roughly 1.5–1.8g per kg of body weight for most people. Eating too much protein can trigger gluconeogenesis (conversion of protein to glucose), which may reduce ketone production in some individuals. However, this is less of a concern for most people than commonly stated; prioritise hitting your protein floor before worrying about excess. Athletes and those focused on muscle gain should aim towards the higher end.
What is a ketogenic ratio and what should mine be?
The ketogenic ratio is the ratio of fat grams to the combined grams of protein and net carbs (fat ÷ (protein + net carbs)). A ratio of 1.5 or higher is generally considered ketogenic for most people. Classic therapeutic ketogenic diets use ratios of 3:1 or 4:1, but a ratio of 1.5–2.0 is sufficient for fat loss and general health purposes.
How long does it take to get into ketosis?
Most people enter ketosis within 2–4 days of restricting carbs below 20–30g net carbs per day, provided glycogen stores are depleted. Exercise can accelerate the process. Full fat adaptation — where the body efficiently burns ketones as primary fuel — typically takes 4–6 weeks. Symptoms of keto adaptation (fatigue, brain fog, reduced performance) usually resolve within 2–3 weeks.
Can I build muscle on keto?
Yes, muscle gain is possible on a ketogenic diet, but it is slower compared to a higher-carbohydrate approach. Carbohydrates create an anabolic hormonal environment and replenish muscle glycogen more efficiently. If muscle gain is your primary goal, a targeted keto diet (adding 25–50g of fast carbs around training) or a cyclical approach may be more effective than strict keto.
What is the difference between total carbs and net carbs?
Total carbohydrates include all carbs in a food, including dietary fibre. Net carbs are total carbs minus fibre (and in some systems, sugar alcohols). Fibre is subtracted because it is not digested and absorbed into the bloodstream — it does not raise blood sugar or insulin. On keto, net carbs are the relevant metric for managing ketosis.