Why use this calculator
A ketogenic diet requires precise macronutrient ratios to maintain ketosis. This calculator helps you determine exactly how many grams of carbs, protein, and fat to eat daily.
How to use it
Select your preferred unit system (metric or imperial), then enter your body stats and activity level. Set your desired calorie deficit percentage. The calculator will compute your TDEE, apply the deficit, and split calories into the standard keto ratio of 5% carbs, 25% protein, and 70% fat.
The formula
TDEE = BMR x Activity Factor. Target Calories = TDEE x (1 - Deficit%). Carbs = 5% of calories / 4 cal/g. Protein = 25% of calories / 4 cal/g. Fat = 70% of calories / 9 cal/g.
Worked examples
170 lb male, sedentary, 20% deficit
About 1,627 kcal with 20g carbs, 102g protein, 127g fat
140 lb female, light activity, 15% deficit
About 1,524 kcal with 19g carbs, 95g protein, 119g fat
When people use it
- Starting a ketogenic diet with proper macro targets
- Adjusting keto macros when weight loss stalls
- Planning keto-friendly meal prep
- Transitioning from standard dieting to keto
Tips
- Keep net carbs under 20-25g per day to stay in ketosis
- Adequate protein intake prevents muscle loss on keto
- Increase sodium, potassium, and magnesium intake to avoid keto flu
- Track your macros closely during the first few weeks of keto
Questions people ask
- How long does it take to enter ketosis?
- Most people enter ketosis within 2-4 days of limiting carbs to under 20-50g per day. Full fat-adaptation can take 2-4 weeks.
- Is a 20% deficit too aggressive?
- A 20% deficit is moderate and sustainable for most people. If you feel fatigued, try reducing to 10-15%. Never exceed a 30% deficit without medical supervision.
- Can I eat too much protein on keto?
- Moderate protein intake (25% of calories) is fine. Very excessive protein can theoretically reduce ketone production, but this is rarely an issue in practice.