The amount of carbs to eat at breakfast depends on several factors, including the type of dietary pattern you're following, how carbs make you feel in the morning, your preferences, your activity level, and what else you'll be eating that day.
For example, people following a keto diet with a limit of 25 grams of net carbs per day may not want to exceed 7 or 8 grams of net carbs at breakfast, whereas people following more flexible low carb diets may be able to have a breakfast containing 25–40 grams of carbs.
People who have really active jobs or lifestyles may want a higher carb intake at breakfast because carbs provide a readily accessible form of energy (25).