Keto Macro Calculator
Calculate your fat, protein, and net carb targets for a ketogenic diet.
Optional: Enter weight and body fat to calculate protein from lean mass.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
Can't find what you need?
Request a ToolHow to Use the Keto Macro Calculator
A ketogenic diet achieves nutritional ketosis by severely restricting carbohydrates and replacing those calories with fat. Calculating your specific macros prevents common mistakes like eating too many carbs or too little protein. Here is how to use this calculator:
- Enter your daily calorie goal. Use the TDEE Calculator to find your maintenance calories, then set your goal below maintenance to lose fat, at maintenance to recompose, or slightly above to build muscle.
- Set your net carb limit. Most people achieve and maintain ketosis on 20-50g of net carbs per day. 25g is a conservative starting point. Net carbs = total carbs minus fiber.
- Set your protein ratio. The default of 0.8g per lb of lean mass is a common keto recommendation. Higher protein (0.9-1.0g) is better for preserving muscle during weight loss.
- Optional: Enter weight and body fat. If you know your body fat percentage, the calculator uses your lean mass to set protein more precisely than a percentage-based approach.
About Ketogenic Macros
Standard keto macro ratios are typically 70-75% of calories from fat, 20-25% from protein, and 5% or fewer from carbohydrates. This calculator calculates carbs first (from your net carb limit), then protein (based on lean mass or a percentage estimate), with fat filling in the remaining calories. Fat is the flexible macronutrient on keto: it goes up or down to adjust total calories.
Protein is the most important macro to get right on keto. Too little protein accelerates muscle loss. Too much protein can theoretically reduce ketone production through gluconeogenesis, though this concern is overstated in most research. For most active people, 0.7-1.0g of protein per pound of lean body mass hits the sweet spot for muscle retention without significantly impairing ketosis.
Frequently Asked Questions
How many net carbs can I eat on keto?
Most people achieve ketosis at 20-50g of net carbs per day. 20-25g is the strictest approach and works for the vast majority. Some individuals with higher metabolic flexibility and more physical activity can maintain ketosis up to 50g or occasionally higher. Net carbs are calculated by subtracting dietary fiber from total carbohydrates, since fiber is not digested and does not raise blood glucose.
Does too much protein kick you out of ketosis?
This is a common keto concern, but the evidence suggests it is overstated for most people. The body does convert some amino acids to glucose through gluconeogenesis, but this process is primarily demand-driven, not supply-driven. Research shows that most people can consume moderate to high protein (up to 1.0g per lb of body weight) while maintaining adequate ketone levels for the metabolic benefits of keto. Prioritize sufficient protein over avoiding it.
What are net carbs and how do I calculate them?
Net carbs are the carbohydrates that your body can digest and convert to glucose. They are calculated by subtracting dietary fiber from total carbohydrates: Net Carbs = Total Carbs - Fiber. Sugar alcohols like erythritol can also be subtracted, but others like maltitol should be counted at half their value. The keto carb limit refers to net carbs, not total carbs. A food with 10g total carbs and 7g fiber has only 3g net carbs.
How long does it take to reach ketosis?
Most people enter a state of nutritional ketosis within 2-4 days of maintaining their carb limit. The timeline depends on how depleted your glycogen stores are, your activity level, and your individual metabolic rate. Exercise accelerates glycogen depletion and can shorten the time to ketosis. Full keto-adaptation, where the body becomes maximally efficient at using fat for fuel, takes 4-8 weeks of consistent carb restriction.