One 100 g serving of mcdonald's, filet-o-fish has 282 calories, 26.4 g of carbs, and 1.4 g of fiber.
Full macro and micronutrient breakdown, plus how this compares across diets, is on the McDONALD'S, FILET-O-FISH nutrition facts page.
Source: USDA FoodData Central - SR Legacy (2018-04)