A standard ketogenic diet gets 70 to 80% of calories from fat, 10 to 20% from protein, and 5 to 10% from carbohydrates. For someone eating 2,000 calories a day, that translates to roughly 155 to 178 grams of fat, 50 to 100 grams of protein, and 20 to 50 grams of carbohydrates. But those percentages are starting points. Your ideal macros shift depending on your calorie needs, activity level, and whether you’re trying to lose weight or maintain it.
The Standard Keto Ratio
The core principle of keto is straightforward: cut carbs low enough that your body switches from burning glucose to burning fat for fuel. This metabolic state, called ketosis, generally kicks in when total carbohydrate intake drops below 50 grams per day. Many people aim for 20 to 30 grams to ensure they stay in ketosis consistently, especially in the first few weeks.
Protein is kept moderate compared to other low-carb diets. Eating too much protein can interfere with ketosis because your body can convert excess amino acids into glucose. That said, “moderate” doesn’t mean low. Most people land between 0.6 and 1.0 grams of protein per pound of lean body mass, which keeps muscles supplied without knocking you out of ketosis. If you weigh 170 pounds and estimate about 30% body fat, your lean mass is around 119 pounds, putting your protein target somewhere between 70 and 119 grams daily.
Fat fills in the rest of your calories. Since fat has 9 calories per gram (compared to 4 for protein and carbs), it doesn’t take as much volume as you might expect. A tablespoon of olive oil is 14 grams of fat, and an avocado has about 21 grams.
How to Calculate Your Specific Numbers
Percentages are useful as a framework, but grams are what you actually track. Here’s how to work out your personal targets at a 2,000-calorie intake:
- Carbs (5 to 10%): 25 to 50 grams. Most people start at 20 to 25 grams of net carbs for the first two to four weeks, then experiment upward to find their personal threshold.
- Protein (10 to 20%): 50 to 100 grams. Lean toward the higher end if you’re active or trying to preserve muscle during weight loss.
- Fat (70 to 80%): 156 to 178 grams. This number drops if you’re eating fewer total calories for weight loss.
If your daily calorie target is 1,600 instead of 2,000 (a common range for people losing weight), those fat grams drop to roughly 124 to 142, while protein and carb targets stay similar. Protein and carb grams are fairly fixed by your body’s needs. Fat is the flexible lever you adjust up or down based on your calorie goal.
Net Carbs vs. Total Carbs
Most keto followers track net carbs rather than total carbs. The formula is simple: total carbohydrates minus fiber equals net carbs. Fiber passes through your digestive system without raising blood sugar, so it doesn’t count against your carb budget. A cup of broccoli has about 6 grams of total carbs but 2.4 grams of fiber, giving you roughly 3.6 net carbs.
Sugar alcohols (found in many “keto-friendly” packaged foods) are a bit different. The general rule from diabetes nutrition guidelines is to subtract half the grams of sugar alcohol from the total carbohydrate count, not the full amount. So if a protein bar lists 29 grams of total carbs and 18 grams of sugar alcohols, you’d subtract 9 (half of 18), counting it as 20 grams of net carbs. Some sugar alcohols like erythritol have virtually no glycemic impact and are often fully subtracted, but for most others, the half-subtraction rule is more accurate.
Adjusting Fat for Weight Loss
This is where many people get confused. The 70 to 80% fat guideline assumes you’re eating at or near maintenance calories. If your goal is fat loss, you want your body to burn its own stored fat for part of that energy, which means you eat less dietary fat while keeping carbs and protein the same.
In practice, someone targeting weight loss might eat closer to 60 to 70% of their (reduced) calories from fat. The carb ceiling stays at 20 to 50 grams. Protein stays the same or even increases slightly to protect muscle mass during a calorie deficit. The fat portion simply shrinks because you’re eating fewer total calories and your body covers the gap by pulling from its own fat stores. You’re still in ketosis because carbs remain low. You’re just not adding as much fat on top of what your body is already providing.
Why Protein Deserves Extra Attention
Old-school keto advice warned people to keep protein very low, but this is one area where the practical wisdom has shifted. Moderate protein is important for preserving lean muscle, supporting immune function, and keeping you full between meals. The fear that protein will “kick you out of ketosis” is overstated for most people eating in a normal range. It takes a significant protein surplus to trigger meaningful glucose production from amino acids.
A reasonable starting point is 0.7 to 0.8 grams of protein per pound of your target body weight. If you’re 200 pounds aiming to get to 170, base your protein calculation on 170 pounds, giving you about 119 to 136 grams of protein per day. Active individuals, especially those doing resistance training, can push toward 1.0 gram per pound of lean mass without issues.
Electrolytes: The Hidden Macro
Electrolytes aren’t technically macronutrients, but they’re so critical on keto that ignoring them will undermine everything else. When you cut carbs drastically, your kidneys excrete more sodium and water. This pulls potassium and magnesium along with it, which is why many new keto dieters experience headaches, fatigue, muscle cramps, and brain fog in the first week or two (often called “keto flu”).
The daily targets that tend to prevent these symptoms are 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 surprises people because it’s higher than general dietary guidelines, but the math changes when your kidneys are flushing sodium at an accelerated rate. Salting your food generously, drinking broth, and eating potassium-rich foods like avocado and leafy greens covers a lot of this naturally.
Watch Your Fiber Intake
One consistent finding in studies of ketogenic diets is that fiber intake drops dramatically. Research has documented average fiber intakes as low as 6 grams per day on keto, well below the recommended 25 to 28 grams. Low fiber can lead to constipation and may affect gut health over time.
The fix is deliberate food choices. Non-starchy vegetables like spinach, kale, cauliflower, and zucchini add fiber without many net carbs. Chia seeds (about 5 grams of fiber per tablespoon with under 1 net carb), flaxseed, and hemp hearts are easy additions. Since fiber is subtracted from your net carb count, eating high-fiber foods doesn’t compete with your carb budget the way it might seem at first glance.
Medical Keto Is a Different Formula
If you’ve seen references to 4:1 or 3:1 keto ratios, those come from the therapeutic ketogenic diet used in clinical settings, primarily for epilepsy management. The ratio describes grams of fat to grams of everything else (protein and carbs combined). A 4:1 ratio means 4 grams of fat for every 1 gram of protein and carbs, pushing fat intake to 85 to 90% of total calories. This is far more restrictive than what most people follow for general health or weight management and requires medical supervision. The standard nutritional keto diet that most people follow sits closer to a 1.5:1 or 2:1 ratio.