A standard ketogenic diet calls for roughly 70 to 80% of your daily calories from fat, 10 to 20% from protein, and just 5 to 10% from carbohydrates. On a 2,000-calorie diet, that works out to about 165 grams of fat, 75 grams of protein, and 40 grams of carbohydrates per day. Those percentages are a starting framework, though, not a rigid prescription. Your ideal numbers shift depending on your body weight, activity level, and whether your goal is weight loss, muscle maintenance, or simply staying in ketosis.
The Three Macros and What They Do on Keto
Each macronutrient plays a specific role when you’re trying to keep your body in ketosis, the metabolic state where you burn fat for fuel instead of glucose.
Carbohydrates are the macro you restrict most aggressively. Most people need to stay under 20 to 50 grams of net carbs per day to enter and maintain ketosis. Net carbs are calculated by taking total carbohydrates and subtracting fiber and sugar alcohols, since your body doesn’t digest or absorb those. A food label showing 12 grams of total carbs with 5 grams of fiber has 7 grams of net carbs. If you’re new to keto, starting at 20 grams of net carbs and adjusting upward gives you the best chance of reaching ketosis quickly.
Protein is kept moderate compared to other low-carb diets. Your body can convert amino acids from protein into glucose through a process called gluconeogenesis, and eating too much protein can slow or prevent ketosis. The goal is enough protein to preserve your muscle mass without tipping over into glucose production. A common target is 0.6 to 1.0 grams of protein per pound of lean body mass, which for most people lands in that 10 to 20% calorie range.
Fat fills in the rest and becomes your primary fuel source. At 70 to 80% of calories, fat is by far the largest share of what you eat. This is what makes keto feel so different from conventional diets: avocados, olive oil, nuts, cheese, and fatty cuts of meat become staples rather than things you limit.
How to Calculate Your Personal Targets
Percentages are helpful for understanding the diet’s structure, but gram targets are what you actually track day to day. Here’s how to find yours.
Start by estimating your total daily calorie needs. This depends on your age, sex, height, weight, and activity level. A sedentary woman might need around 1,600 calories, while an active man could need 2,500 or more. Once you have that number, work backward through each macro:
- Carbs first: Set your net carb target at 20 to 40 grams. Multiply by 4 (since carbs have 4 calories per gram) to get the calories from carbs.
- Protein second: Aim for 0.6 to 1.0 grams per pound of lean body mass. If you weigh 180 pounds and estimate roughly 30% body fat, your lean mass is about 126 pounds, putting your protein target between 76 and 126 grams. Multiply by 4 to get protein calories.
- Fat fills the gap: Subtract your carb and protein calories from your total calorie target. Divide what’s left by 9 (fat has 9 calories per gram) to get your daily fat grams.
For someone eating 1,800 calories with 25 grams of net carbs and 90 grams of protein, the math looks like this: 100 calories from carbs plus 360 from protein leaves 1,340 calories for fat, or about 149 grams. That works out to roughly 74% fat, 20% protein, and 6% carbs.
Why Fat Isn’t Always a Hard Target
If your goal is weight loss, fat is best treated as a flexible lever rather than a number you need to hit every day. Carbs and protein are your anchors: you keep carbs low to stay in ketosis and protein adequate to protect muscle. Fat is what you use to manage hunger and energy. On days when you’re satisfied after meals, you don’t need to add extra butter or oil just to reach a fat percentage.
This distinction matters because keto’s high fat percentage can be misleading. When people force themselves to meet a 75% fat target regardless of appetite, they sometimes eat more calories than they need and stall on weight loss. Letting fat intake vary naturally with your hunger while holding carbs and protein steady tends to produce better results.
Adjustments for Active People
If you exercise regularly, especially with resistance training or endurance work, your protein needs are higher than someone who is sedentary. Aiming for the upper end of the protein range (closer to 1.0 grams per pound of lean mass) helps support muscle repair and recovery. Some athletes on keto push protein to 25% of calories without losing ketosis, though individual responses vary.
Research on elite athletes following ketogenic diets has used protocols around 78% fat and 2.1 grams of protein per kilogram of body weight (about 0.95 grams per pound), with carbs held under 50 grams daily. That higher protein level reflects the increased demand that intense training places on muscle tissue. If you’re doing serious workouts several times a week, prioritize protein over hitting an exact fat percentage.
Endurance athletes sometimes experiment with slightly higher carb intake (targeted around workouts) while still maintaining ketosis the rest of the day. This approach, sometimes called a targeted ketogenic diet, typically adds 15 to 30 grams of fast-digesting carbs before intense sessions.
How to Know If Your Macros Are Working
Nutritional ketosis is defined by blood levels of beta-hydroxybutyrate (a ketone body) between 0.5 and 5.0 mmol/L. You can measure this with blood ketone meters, urine strips, or breath analyzers, though blood meters are the most accurate. Most people reach this range within two to seven days of keeping net carbs under 20 to 30 grams.
You don’t necessarily need to test, though. Practical signs that you’re in ketosis include a metallic or fruity taste in your mouth, noticeably decreased appetite, increased thirst, and sustained energy without the mid-afternoon crash you might be used to. If those signs show up and your carbs are consistently low, your macros are likely in the right range.
Net Carbs vs. Total Carbs
This distinction trips up a lot of people early on. Total carbohydrates on a nutrition label include fiber and sugar alcohols. Your body doesn’t digest fiber, and most sugar alcohols pass through without raising blood sugar, so they’re subtracted from the total to give you net carbs. If a protein bar lists 18 grams of total carbs, 8 grams of fiber, and 5 grams of erythritol, its net carb count is 5 grams.
One caveat: not all sugar alcohols are created equal. Erythritol and allulose have virtually no glycemic impact and can be fully subtracted. Maltitol, on the other hand, does raise blood sugar significantly and should be counted as roughly half its listed grams. When in doubt, check how a specific sugar alcohol ranks on the glycemic index.
Electrolytes Matter as Much as Macros
Getting your fat, protein, and carb ratios right is only part of the equation. When you cut carbs drastically, your kidneys excrete more sodium and water, which pulls potassium and magnesium along with it. This is the main cause of “keto flu,” that collection of headaches, fatigue, cramps, and brain fog that hits in the first week or two.
The daily targets that prevent these symptoms are higher than most people expect: 3,000 to 5,000 mg of sodium, 3,000 to 4,000 mg of potassium, and 300 to 500 mg of magnesium. That sodium number alone is well above what standard dietary guidelines recommend, but it reflects the increased losses that come with very low carb intake. Salting your food generously, drinking broth, eating avocados and leafy greens, and supplementing magnesium can cover these needs. If you feel terrible in your first week on keto, your macros may be perfect while your electrolytes are the actual problem.
Standard Keto vs. Therapeutic Keto
The macros described above apply to the standard ketogenic diet used for weight loss and general health. Therapeutic ketogenic diets, originally developed for epilepsy management, are significantly stricter. A classic therapeutic protocol uses a 4:1 ratio, meaning 4 grams of fat for every 1 gram of combined protein and carbohydrate. That pushes fat to roughly 90% of total calories, with very little room for protein or carbs. A slightly less restrictive 3:1 ratio is sometimes used for adolescents or people who need more protein.
These medical versions require supervision from a healthcare team and careful meal planning. If you’re following keto for weight management or metabolic health, the standard 70 to 80% fat framework gives you much more flexibility and is far easier to sustain long term.