Keto Macro Calculator

Macros (macronutrients) are the three main nutrients your body uses for energy: fat, protein, and carbohydrates. On a ketogenic diet, tracking macros is essential because you need to keep carbs very low (typically under 25g/day) to enter and stay in ketosis, the metabolic state where your body burns fat for fuel instead of glucose.

Keto macros are calculated by first determining your Total Daily Energy Expenditure (TDEE) using your BMR (from height, weight, age, and gender) multiplied by your activity factor. Then a calorie goal is set based on your weight objective. Net carbs are fixed (usually 20-25g), protein is set at roughly 0.7-1g per pound of lean body mass, and the remaining calories are filled with fat.

A standard ketogenic macro split is approximately 70-75% of calories from fat, 20-25% from protein, and 5% or less from carbohydrates. In gram terms, most people aim for 20-50g net carbs, moderate protein (0.6-1g per lb of lean mass), and fat to fill remaining calories. Individual targets vary based on body stats, activity, and goals.

Body fat percentage is used to calculate your Lean Body Mass (LBM), which is your weight minus fat mass. Protein targets are based on LBM rather than total body weight — this prevents overestimating protein needs for people with higher body fat and helps preserve muscle while losing fat.

This calculator uses established formulas (Mifflin-St Jeor for BMR and standard TDEE multipliers) and produces a solid starting estimate for most people. Results are most accurate when you enter your actual body fat percentage. Individual metabolism varies, so treat your output as a starting point and adjust based on real-world results over 2-4 weeks.

Most people lose 1-2 lbs per week on keto when in a moderate calorie deficit. Initial weight loss in the first 1-2 weeks is often faster (3-5 lbs) due to water weight from glycogen depletion. Long-term fat loss depends on consistently maintaining your macro targets and calorie deficit.

Strictly speaking, you don't have to count every gram, but tracking macros — especially net carbs — is strongly recommended, particularly when starting keto. Going over your carb limit is the most common reason people fail to reach or maintain ketosis. Once you're experienced and know your food choices well, some people transition to intuitive eating while still keeping carbs low.

Net carbohydrates are the most critical macro to track on keto. Keeping carbs below your threshold (typically 20-25g net carbs) is what triggers and sustains ketosis. Fat and protein targets matter for energy balance and preserving muscle, but exceeding your carb limit will kick you out of ketosis regardless of how well you manage the other macros.