One 100 g serving of cauliflower, frozen, unprepared has 24 calories, 4.7 g of carbs, and 2.3 g of fiber.
Full macro and micronutrient breakdown, plus how this compares across diets, is on the Cauliflower, frozen, unprepared nutrition facts page.
Source: USDA FoodData Central - SR Legacy (2018-04)