Keto Calculator
Calculate your daily fat, protein, and net carb targets for a ketogenic diet. Results are based on your TDEE (Total Daily Energy Expenditure) and adjusted for your chosen goal.
| Macro | Grams/day | Calories | % of diet |
|---|---|---|---|
| Fat | 187g | 1683 | 76% |
| Protein | 111g | 444 | 20% |
| Net Carbs | 20g | 80 | 4% |
Step 1 — Mifflin-St Jeor BMR (male): BMR = 10×80.0 + 6.25×175.0 − 5×30 + 5 = 1749 cal Step 2 — TDEE = BMR × activity factor: TDEE = 1749 × 1.55 = 2711 cal/day Step 3 — Keto calories (deficit −500): Keto calories = 2211 cal/day Step 4 — Macros: Carbs: 20g × 4 cal/g = 80 cal (4%) Protein: 111g × 4 cal/g = 444 cal (20%) Fat: 187g × 9 cal/g = 1683 cal (76%)
For informational purposes only. Consult a healthcare professional or registered dietitian before starting a ketogenic diet.
What is the Ketogenic Diet?
The ketogenic diet is a high-fat, very low carbohydrate eating pattern designed to shift the body's primary fuel source from glucose to fat-derived ketone bodies. Originally developed in the 1920s as a medical treatment for epilepsy — where it remains a proven therapy — it gained widespread popularity as a weight loss strategy in the 2010s.
Under normal dietary conditions, carbohydrates are broken down into glucose, which enters the bloodstream and fuels cells throughout the body, particularly the brain. When carbohydrate intake is severely restricted (typically below 50g/day), glucose availability drops. The liver then converts stored and dietary fat into ketone bodies — primarily beta-hydroxybutyrate (BHB), acetoacetate, and acetone — which cross the blood-brain barrier and substitute for glucose as a fuel source. This metabolic state is called nutritional ketosis.
Standard Ketogenic Diet Macros
The classic macro breakdown for a standard ketogenic diet (SKD) is:
- Fat: 70–75% of total calories
- Protein: 20–25% of total calories
- Carbohydrates: 5–10% of total calories (20–50g net carbs/day)
These percentages are guidelines. Individual needs vary based on body size, activity level, and metabolic health. This calculator uses your TDEE (calculated with the Mifflin-St Jeor equation) to produce personalized gram targets.
How to Calculate Keto Macros
The calculation follows four steps:
- Calculate BMR using the Mifflin-St Jeor equation based on age, sex, weight, and height
- Calculate TDEE by multiplying BMR by an activity factor (1.2 for sedentary to 1.9 for very active)
- Set calorie target based on goal: subtract 500 for weight loss (~0.5 kg/week), use TDEE for maintenance, or enter a custom value
- Calculate macros: carbs are capped at your net carb limit, protein is set to 20% of calories, fat fills the remaining calories
Example calculation (80 kg male, 30 years, 175 cm, moderate activity, weight loss goal):
BMR = 10 × 80 + 6.25 × 175 − 5 × 30 + 5 = 800 + 1094 − 150 + 5 = 1,749 cal
TDEE = 1,749 × 1.55 = 2,711 cal/day
Keto calories (loss) = 2,711 − 500 = 2,211 cal/day
Net carbs = 20g × 4 cal/g = 80 cal (4%)
Protein = 2,211 × 20% ÷ 4 = 111g/day (444 cal)
Fat = (2,211 − 80 − 444) ÷ 9 = 188g/day (1,687 cal)
Net Carbs vs Total Carbs
Net carbs are the carbohydrates that impact blood sugar and ketosis. The formula is:
Net carbs = Total carbs − Dietary fiber
Dietary fiber is not digested by the human body's enzymes — it passes through the digestive tract largely intact — so it does not raise blood glucose or stimulate an insulin response. For this reason, fiber is subtracted when calculating net carbs for keto purposes.
Some people also subtract certain sugar alcohols (erythritol, xylitol, sorbitol) from the carb count, though this practice varies and depends on individual tolerance.
Types of Ketogenic Diets
| Type | Description | Who it's for |
|---|---|---|
| Standard (SKD) | 70% fat / 20% protein / 5–10% carbs, every day | Most people; general weight loss and health |
| Targeted (TKD) | SKD + 25–50g extra carbs around workouts | Athletes needing glucose for high-intensity training |
| Cyclical (CKD) | 5 keto days + 1–2 high-carb "refeed" days | Advanced athletes, bodybuilders |
| High-Protein | 60% fat / 35% protein / 5% carbs | Those prioritizing muscle retention |
Benefits and Risks of the Ketogenic Diet
Potential benefits supported by research:
- Significant reduction in seizure frequency in drug-resistant epilepsy (established medical use)
- Effective short-term weight loss, often faster initial loss than standard low-calorie diets (partly due to water weight)
- Reduced appetite due to appetite-suppressing effects of ketones and higher protein and fat intake
- Improved insulin sensitivity and lower blood glucose in type 2 diabetes (should be medically supervised)
- Reduced triglycerides and increased HDL cholesterol in many individuals
Potential risks and considerations:
- Keto flu during adaptation (days 1–14)
- Reduced exercise performance, especially in high-intensity sports, during the adaptation period
- Possible increase in LDL cholesterol in some individuals
- Difficult to sustain long-term due to food restrictions
- Risk of nutrient deficiencies (vitamins C, B vitamins, magnesium, potassium) if not carefully planned
- Not recommended without medical supervision for people with type 1 diabetes, liver or pancreatic disease, or those on certain medications
Frequently Asked Questions
What is the ketogenic diet?
The ketogenic (keto) diet is a very low carbohydrate, high-fat diet that shifts the body into a metabolic state called ketosis. In ketosis, the liver converts fat into ketone bodies, which become the primary fuel source for the brain and muscles instead of glucose. A standard ketogenic diet typically provides 70–75% of calories from fat, 20–25% from protein, and 5–10% from carbohydrates.
How many carbs do I need to stay in ketosis?
Most people enter and maintain ketosis with fewer than 20–50 grams of net carbohydrates per day. Net carbs are total carbohydrates minus dietary fiber (and sometimes sugar alcohols). Strict ketogenic protocols typically limit net carbs to 20g/day. Some people, especially those who are physically active, may maintain ketosis at up to 50g net carbs per day. Individual thresholds vary.
What is the difference between net carbs and total carbs?
Total carbohydrates include all forms of carbohydrate in a food: starches, sugars, and dietary fiber. Net carbs are calculated by subtracting dietary fiber from total carbs (net carbs = total carbs − fiber). Fiber is subtracted because it is not digested and does not raise blood glucose or interfere with ketosis. Some also subtract sugar alcohols like erythritol, though others do not.
How long does it take to enter ketosis?
Most people enter ketosis within 2–4 days of restricting carbohydrates to under 20–50g per day, provided they maintain the restriction consistently. The timeframe depends on how quickly glycogen stores (stored glucose in muscles and liver) are depleted. Exercise accelerates this process by burning through glycogen faster. Blood ketone levels above 0.5 mmol/L indicate nutritional ketosis.
What is keto flu and how do I avoid it?
Keto flu refers to a collection of symptoms — fatigue, headache, brain fog, irritability, muscle cramps — that some people experience during the first 1–2 weeks of starting a ketogenic diet. It is caused primarily by electrolyte loss: as glycogen is depleted, the kidneys excrete more sodium, potassium, and magnesium. To minimize keto flu: increase sodium intake (add salt to food or drink bouillon), supplement potassium and magnesium, stay well hydrated, and transition gradually by reducing carbs over 1–2 weeks rather than cutting them all at once.
Is protein intake important on keto?
Yes. Adequate protein is critical on a ketogenic diet to preserve muscle mass. The minimum recommendation is 0.8g of protein per kg of body weight per day. Athletes and those aiming to build or maintain muscle should target 1.6–2.2g/kg. Consuming very high protein (above 3g/kg) can theoretically reduce ketosis via gluconeogenesis — the liver can convert excess amino acids to glucose — but this effect is overstated in most practical scenarios.
Medical Disclaimer: For informational purposes only. Consult a healthcare professional or registered dietitian before starting a ketogenic diet, especially if you have diabetes, kidney disease, liver disease, cardiovascular conditions, or are pregnant or breastfeeding. The ketogenic diet significantly alters metabolism and may interact with medications.
Related Calculators
- Macro Calculator — custom fat, protein, and carb targets for any diet goal
- Calorie Calculator — daily calorie needs using Mifflin-St Jeor formula
- TDEE Calculator — Total Daily Energy Expenditure with activity multiplier
- BMI Calculator — Body Mass Index with healthy weight range
- Protein Calculator — daily protein needs based on weight and goals