McDonald's Filet-O-Fish: calories, nutrition, ingredients and allergens

A McDonald's Filet-O-Fish contains 316 kcal. With small fries the total reaches 566 kcal. With medium fries the total reaches 646 kcal. With large fries the total reaches 746 kcal. Adding a medium Coca-Cola to a medium meal brings the total to 826 kcal. The Filet-O-Fish represents 16% of the 2,000 kcal adult daily reference intake and is one of the lower-calorie hot items on the core McDonald's menu.

Per item: 316 kcal, 13g fat (2.8g saturated), 36g carbohydrate (5g sugar), 15g protein, 1g salt. The saturated fat at 2.8g is 14% of the adult daily guideline — among the lowest of any hot sandwich in this guide. The sugar at 5g is 17% of the adult daily free sugar limit. The salt at 1g is 17% of the adult daily limit and 33% of the daily limit for a child aged 4 to 6.

The fish fillet in a McDonald's Filet-O-Fish is MSC-certified sustainable white fish — typically Alaska pollock or hoki depending on availability. MSC (Marine Stewardship Council) certification means the fish is sourced from fisheries assessed as sustainable. The fillet is a whole portion of white fish in a breaded coating rather than reformed or minced fish — making the fish fillet itself one of the more minimally processed components in the sandwich.

The Filet-O-Fish is served with half a processed cheddar cheese slice rather than a full slice. This is a longstanding feature of the product design, intended to balance the flavour without overpowering the fish. The half slice contributes approximately 0.8g of saturated fat and 0.2g of salt. It is the same processed cheddar used across the burger range, and the half slice is the source of the milk allergen declaration on the Filet-O-Fish.

A McDonald's Filet-O-Fish contains wheat, fish and milk as declared allergens. The milk comes from the half processed cheese slice. It may also contain traces of barley, rye and sesame from shared kitchen equipment. It does not contain eggs, soya, crustaceans, celery, mustard, molluscs or lupin as declared allergens — despite the tartare sauce containing egg yolk and mustard in its ingredient list, neither is declared as a named allergen.

A McDonald's Filet-O-Fish contains 316 kcal compared to 371 kcal in a McChicken Sandwich — 55 fewer calories. Both have similar low saturated fat at 2.8g versus 2.2g. Sugar is the same at 5g. Salt is the same at 1g. The Filet-O-Fish has fewer calories and slightly more saturated fat. The Filet-O-Fish contains fish and milk allergens; the McChicken Sandwich contains soya but no milk or fish allergens.

The tartare sauce in a McDonald's Filet-O-Fish contains egg yolk in its ingredient list — alongside rapeseed oil, water, gherkin, vinegar, sugar and stabilisers. However McDonald's UK does not declare egg as a named allergen on the Filet-O-Fish. This is consistent with the pattern seen across the McChicken Sandwich and Bacon Mayo Chicken. For anyone with a diagnosed egg allergy, always check the current McDonald's UK allergen booklet before ordering.

The Filet-O-Fish is one of the more moderate hot options on the McDonald's menu for children on calories, saturated fat and sugar. The salt at 1g uses 33% of the daily limit for a child aged 4 to 6 — the same as the Hamburger and among the lowest of any hot sandwich. It contains fish and milk allergens. For children who eat fish, it is among the better nutritional options on the core menu. It is not on the Happy Meal menu.

Yes. A McDonald's Filet-O-Fish falls into NOVA group 4, ultra-processed foods. The steamed bun contains emulsifiers and dextrose. The tartare sauce contains stabilisers. The processed cheese slice contains emulsifying salts. The fish fillet's breaded coating contains industrial processing agents. Despite the fish fillet itself being a whole-cut sustainable species, the overall assembly and additive content place the item in NOVA 4.

A McDonald's Filet-O-Fish medium meal — sandwich with medium fries and medium Coca-Cola — contains approximately 826 kcal, 40g of free sugar (5g from the sandwich and 35g from the drink), approximately 1.6g of salt from the sandwich and fries combined, and approximately 4-5g of saturated fat. Substituting water for the Coca-Cola reduces the meal to approximately 646 kcal and brings free sugar down to 5g.