Keto Calculator

How to Use the Keto Calculator

Our keto macro calculator personalizes your daily fat, protein, and net carb targets for a ketogenic diet. Enter your body measurements (weight, height, age, gender), select your activity level and weight goal, and the calculator instantly computes your Total Daily Energy Expenditure (TDEE) and breaks it into keto-friendly macro ratios. Net carbs are automatically capped at 25 grams per day to help you maintain ketosis, with any excess carb calories redistributed to fat.

The ketogenic diet works by drastically reducing carbohydrate intake so your body shifts from burning glucose to burning fat for fuel — a metabolic state called ketosis. Getting the right macro balance is critical: too many carbs will kick you out of ketosis, while too little protein can lead to muscle loss. This calculator takes the guesswork out of keto meal planning by providing precise, science-based targets tailored to your body.

The Science Behind Keto Macros

The standard ketogenic diet follows a macro ratio of approximately 70% fat, 25% protein, and 5% carbohydrates. This ratio forces the liver to convert fatty acids into ketone bodies, which become the primary fuel source for the brain and muscles. The calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate, then applies an activity multiplier to determine your TDEE. From there, it distributes calories according to keto ratios and adjusts for your weight goal.

Why Net Carbs Are Capped at 25g

Research shows that most people enter ketosis when net carbohydrate intake drops below 20-50 grams per day. This calculator caps net carbs at 25 grams — a target that works for the vast majority of people regardless of body size. Any calories that would have come from excess carbs are automatically redirected to fat, ensuring your total calorie target remains accurate while keeping you firmly in ketosis territory.

Adjusting for Your Weight Goal

The calculator offers three goal settings. Maintain uses your full TDEE. Lose weight applies a 500-calorie daily deficit, which translates to roughly one pound of fat loss per week. Gain weight adds a 500-calorie surplus for lean mass building. All adjustments maintain the same keto macro percentages, so you stay in ketosis regardless of whether you are cutting, maintaining, or bulking.

Frequently Asked Questions

What macros should I eat on keto?

A standard ketogenic diet typically targets 70% of calories from fat, 25% from protein, and 5% from carbohydrates. Most people should aim for 20-25 grams of net carbs per day to maintain ketosis. Protein intake should be adequate to preserve muscle mass, and the remaining calories come from healthy fats.

How many carbs can I eat and stay in ketosis?

Most people need to limit net carbs to 20-25 grams per day to enter and maintain ketosis. Some individuals with higher activity levels may tolerate up to 50 grams. Net carbs are calculated as total carbohydrates minus fiber and sugar alcohols.

How does the keto calculator determine my calories?

The calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate based on weight, height, age, and gender. It then multiplies by an activity factor for TDEE, and adjusts based on your weight goal.

Should I eat more fat or protein on keto?

On keto, fat is your primary energy source at about 70% of calories. Protein should be moderate at about 25% — enough to preserve muscle but not so much that excess converts to glucose through gluconeogenesis.

How long does it take to enter ketosis?

Most people enter ketosis within 2-4 days of restricting carbohydrates to 20-25 grams per day. Staying hydrated and supplementing electrolytes can help ease the transition period.