How much fat should you eat while on keto? The definitive guide

October 14, 2025 •

4 min read

The ketogenic diet, commonly known as keto, is a low-carbohydrate, high-fat eating plan where 70-80% of daily calories typically come from fat. Knowing how much fat you should eat while on keto is critical for both reaching and maintaining the metabolic state of ketosis.

Quick Summary

The ideal fat intake on a ketogenic diet varies based on individual goals like weight loss, maintenance, or muscle gain. This amount is calculated by first determining your total daily energy needs and then subtracting the calories from your personalized protein and very low carbohydrate targets.

Key Points

Calculate Your Macros: Do not guess your fat intake. Accurately calculate your daily calories, protein, and net carbs to determine your optimal fat grams.
Fat for Fuel vs. Fat for Satiety: On keto, you eat fat to provide energy (fuel) and to feel full (satiety), but not necessarily to add calories if your goal is weight loss.
Prioritize Healthy Fats: Focus on monounsaturated and polyunsaturated fats from sources like olive oil, avocados, and nuts, while minimizing unhealthy processed fats.
Adjust Based on Goals: For weight loss, aim for a moderate fat intake to create a caloric deficit. For maintenance or muscle gain, increase your fat intake to meet your energy needs.
Protein Matters Too: Consuming moderate protein is essential, as too little can cause muscle loss, while too much can interfere with ketosis via gluconeogenesis.
Listen to Your Body: Pay attention to your energy levels and satiety cues. If you're always hungry, you may need to slightly increase your fat intake; if you're not losing weight, you may need to reduce it.

Understanding the Role of Fat on Keto

On a ketogenic diet, fat is no longer just a component of your meals—it becomes the primary fuel source for your body. This metabolic shift, known as ketosis, occurs when carbohydrate intake is low enough that your body produces ketones from fat for energy. This is a significant departure from a typical diet where carbohydrates are the main fuel.

Unlike protein, which should be consumed in moderate amounts to prevent the body from converting it to glucose via gluconeogenesis, fat is flexible and is adjusted based on your specific goals. For example, a person aiming for weight loss will consume less fat to encourage the body to burn its own stored fat for energy, while someone maintaining weight will eat more.

Step-by-Step: Calculating Your Keto Fat Intake

Calculating your personal fat macro requires a few key steps. It's not about eating as much fat as possible, but rather the right amount to reach your goals while still feeling satisfied.

Step 1: Determine Your Total Daily Energy Expenditure (TDEE)

Your TDEE is the number of calories your body burns in a day, factoring in your basal metabolic rate (BMR) and activity level. Online calculators can help, but a standard formula like the Mifflin-St. Jeor equation provides a solid starting point.

Men: (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5
Women: (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161

Once you have your BMR, you'll multiply it by an activity factor (e.g., sedentary, moderately active) to get your TDEE.

Step 2: Set Your Carb and Protein Goals

Carbohydrates: For most people on a standard keto diet, keeping net carbs between 20 and 50 grams per day is the target. Multiply your carb grams by 4 to find the calories from carbs.
Protein: Moderate protein intake is crucial. A common guideline is 0.6 to 1.0 grams per pound of lean body mass, depending on your activity level. Multiply your protein grams by 4 to get the calories from protein.

Step 3: Calculate Your Fat Intake

Your fat intake fills the remaining calories needed to meet your TDEE. Subtract your carb and protein calories from your total daily calorie goal, then divide the result by 9 (since there are 9 calories per gram of fat).

For example, if your total calorie goal is 2000:

Carbs: 25g x 4 = 100 calories
Protein: 100g x 4 = 400 calories
Remaining calories for fat: 2000 - 100 - 400 = 1500 calories
Grams of fat: 1500 / 9 ≈ 167 grams

Healthy vs. Unhealthy Fat Sources on Keto

Not all fats are created equal. Prioritizing quality sources of fat is essential for overall health and avoiding negative health effects.


Healthy Fats	Unhealthy Fats
Avocados & Avocado Oil	Processed Seed Oils (e.g., corn, canola)
Nuts (macadamia, pecans, walnuts)	Trans Fats (hydrogenated oils)
Seeds (chia, flax, hemp)	Deep-Fried Foods
Olive Oil (extra virgin)	Excess Processed Meats (bacon, sausage)
Fatty Fish (salmon, sardines)	Most Margarines
Coconut Oil & MCT Oil
Grass-fed Butter & Ghee

Adjusting Fat for Different Goals

Weight Loss: Your dietary fat intake should meet your needs for satiety and energy but not provide a calorie surplus. The goal is to encourage your body to burn its own stored fat. If weight loss stalls, slightly reducing fat intake can help create a larger caloric deficit.
Weight Maintenance: Once you've reached your target weight, you can increase your fat intake to match your maintenance-level TDEE. This ensures your body continues to operate on fat-based energy without drawing from stored fat.
Gaining Muscle: A calorie surplus is needed to build muscle mass. This means increasing your fat intake beyond maintenance levels while keeping carbs low and protein moderate to high.

Practical Ways to Increase Healthy Fat Intake

Add a tablespoon of MCT or coconut oil to your morning coffee.
Drizzle extra-virgin olive oil generously over salads and vegetables.
Incorporate fatty fish like salmon or mackerel into your meals several times a week.
Use avocados as a base for sauces or as a side dish.
Snack on keto-friendly nuts and seeds like macadamia nuts or chia seeds.
Create "fat bombs" using coconut oil, nut butter, and cocoa powder for a high-fat snack.

For additional support and meal plan ideas, resources like those from Harvard Health can provide valuable, science-backed information on ketogenic dieting.

Conclusion: The Right Fat Balance is Key

Eating the right amount of fat on a keto diet is a personalized process, not a one-size-fits-all rule. While the percentage might seem high, the correct intake in grams is determined by your individual calorie needs and health goals. By focusing on healthy, high-quality fats and calculating your personal macros, you can ensure your body has the energy it needs to thrive in a state of ketosis, whether your goal is weight loss, maintenance, or better metabolic health.

Frequently Asked Questions

A standard ketogenic diet typically consists of 70% to 80% of calories from fat, 10% to 20% from protein, and 5% to 10% from carbohydrates.

First, find your total daily calorie needs. Then, calculate your calories from your protein and carb goals. The remaining calories are your fat calories. Divide this number by 9 (calories per gram of fat) to get your daily fat grams.

Yes. While fat is the primary energy source, consuming too much fat can prevent weight loss by exceeding your daily calorie needs. You still need to manage your overall calorie intake.

No. Focus on healthy fats like those from avocados, nuts, seeds, and olive oil, and limit processed trans fats and excessive saturated fats from sources like highly processed meats.

You can add fat by drizzling olive oil on salads, adding nuts and seeds to your meals, incorporating fatty fish, or using healthy oils in your cooking.

On keto, fat is both. Your body uses dietary fat and stored body fat for fuel. Additionally, high fat and moderate protein intake help regulate hunger hormones, leading to increased feelings of fullness.

Yes, your fat intake should be adjusted based on your goals. For weight loss, you'll consume slightly less fat to create a calorie deficit. For maintenance, you'll increase fat to match your higher energy needs.