Tuna Mayo Footlong Sub: calories and sugar by portion and age

Subway Tuna Mayo Footlong Sub, creamy tuna mayo with lettuce, cucumber and red onion in Italian white bread on white paper, nutrition and calories

Boone’s analysis puts Subway Tuna Mayo Footlong Sub at 40% of an adult’s daily calories, 120% of the daily salt limit for a child aged 4 to 6 and 2.9 teaspoons of free sugar.

How many calories are in a Subway Tuna Mayo Footlong Sub? It contains 800 kcal, 32g of fat (6.8g saturated), 13.2g of sugar and 3.6g of salt.

Subway calculates this figure on Italian White bread, the filling, and onion, cucumber and lettuce. Cheese, sauces and extras are not included.

Subway’s footlong figures are its 6 inch figures doubled.

Build a full meal with our nutrition calculator

Use the Boone meal calculator to build a full meal rather than view this item on its own. Add a sub, a side, a cookie, cheese or a sauce, then choose your age and sex for a more accurate view of how a Tuna Mayo Footlong Sub fits into a day.

Nutrition information

Nutrition information: Subway Tuna Mayo Footlong Sub

Energy	800 kcal
Fat	32g
of which saturates	6.8g
Carbohydrate	86g
of which sugars	13.2g
Fibre	4.8g
Protein	44g
Salt	3.6g

Nutrition figures are Subway UK and ROI published data (September 2026), per item as sold, calculated on Italian White bread, the filling, and onion, cucumber and lettuce, before cheese, sauces or extras. Footlong figures are Subway’s 6 inch figures doubled. Boone converts them to the portion and age comparisons on this page.

Subway Tuna Mayo Footlong Sub contains 800 kcal, which is 40% of the 2,000 kcal adult daily reference intake. It provides 32g of total fat, of which 6.8g is saturated, 13.2g of sugar, 3.6g of salt and 44g of protein.

The saturated fat content of 6.8g represents 34% of the adult daily guideline of 20g. It also provides 4.8g of fibre, 16% of the 30g adult daily recommendation.

Subway gives the portion weight as 400g, which works out at 200 kcal per 100g.

Sugar in Subway Tuna Mayo Footlong Sub

Subway Tuna Mayo Footlong Sub contains 11.4g of free sugar per standard serving (2.9 teaspoons). The total sugar figure Subway publishes is 13.2g; Boone estimates the difference is naturally present in the onion, cucumber and lettuce and does not count towards the limits below. High sugar

The NHS free sugar limit is 30g per day for adults, 24g for children aged 7 to 10, and 19g for children aged 4 to 6. Free sugar excludes the sugars naturally present in milk and whole fruit and vegetables.

Free sugar by portion: Subway Tuna Mayo Footlong Sub

Portion	Adult (female) 30g	Adult (male) 30g	Age 11 to 17 30g	Age 7 to 10 24g	Age 4 to 6 19g
Per portion	11.4g 38%	11.4g 38%	11.4g 38%	11.4g 48%	11.4g 60%

Teaspoons: 2.9 tsp

Boone calculates these percentages from Subway UK published nutrition data against UK Dietary Reference Values and NHS free sugar and salt limits. Free sugar, salt, calories and saturated fat are limits to stay under. For guidance only.

Salt in Subway Tuna Mayo Footlong Sub

Subway Tuna Mayo Footlong Sub contains 3.6g of salt per standard serving. High salt

Children have lower salt limits: 3g per day for ages 4 to 6, 5g for ages 7 to 10.

Salt by portion: Subway Tuna Mayo Footlong Sub

Portion	Adult (female) 6g	Adult (male) 6g	Age 11 to 17 6g	Age 7 to 10 5g	Age 4 to 6 3g
Per portion	3.6g 60%	3.6g 60%	3.6g 60%	3.6g 72%	3.6g 120%

Calories in Subway Tuna Mayo Footlong Sub

Subway Tuna Mayo Footlong Sub contains 800 kcal per standard serving. High calorie share

Daily calorie needs vary by age and sex.

Calories by portion: Subway Tuna Mayo Footlong Sub

Portion	Adult (female) 2000 kcal	Adult (male) 2500 kcal	Age 11 to 17 1936 kcal	Age 7 to 10 1553 kcal	Age 4 to 6 1291 kcal
Per portion	800 kcal 40%	800 kcal 32%	800 kcal 41%	800 kcal 52%	800 kcal 62%

Saturated fat in Subway Tuna Mayo Footlong Sub

Subway Tuna Mayo Footlong Sub contains 6.8g of saturated fat per standard serving. Moderate saturated fat

The saturated fat guideline is 20g a day for women and 30g for men, and lower for children.

Saturated fat by portion: Subway Tuna Mayo Footlong Sub

Portion	Adult (female) 20g	Adult (male) 30g	Age 11 to 17 20g	Age 7 to 10 18g	Age 4 to 6 16g
Per portion	6.8g 34%	6.8g 23%	6.8g 34%	6.8g 38%	6.8g 43%

Free sugar vs total sugar

Where the sugar comes from: Subway Tuna Mayo Footlong Sub

Roughly 11.4g of the 13.2g counts as free sugar, or about 2.9 teaspoons. The rest is naturally present in the onion, cucumber and lettuce, which Boone estimates from the vegetables in Subway’s standard build. Subway does not split its sugar figure, so this is a Boone estimate.

NHS daily free sugar limits: 30g for adults and children 11+, 24g age 7 to 10, 19g age 4 to 6.

Ultra-processed food: what is really in it

Processing: Subway Tuna Mayo Footlong Sub

Boone cannot classify this item, because Subway does not publish an ingredient list for it.

NOVA classification is read from an ingredient list. Without one there is no way to count additives, separate raw ingredients from manufactured ones, or say whether an item is ultra-processed. Boone does not estimate a NOVA group, because a guess presented as a classification would be worse than saying nothing.

Ingredients

Subway does not publish an ingredient list for this item

Ingredients: Subway Tuna Mayo Footlong Sub

Subway’s September 2026 UK nutrition and allergen guides do not include an ingredient list for a Subway Tuna Mayo Footlong Sub, and it is under no legal obligation to provide one.

Food made to order in a restaurant counts as non-prepacked under UK food law. The legal requirement is to declare the 14 major allergens, and for large businesses in England to show calories at the point of choice. A full ingredient list is voluntary.

Without one, no page on this site can tell you how many ingredients are in this item, how many of them are manufactured substances, or whether it is ultra-processed. Boone will not estimate any of it.

Subway publishes allergen information for each ingredient, and Boone uses it to build the allergen table below. Recipes change, so always check in restaurant before ordering if you have an allergy.

Allergens at a glance

Subway Tuna Mayo Footlong Sub contains wheat, soya, eggs, fish, mustard and gluten. It may contain traces of sesame.

Allergen information: Subway Tuna Mayo Footlong Sub

Allergen	Status
Wheat	Contains
Rye	Not present
Barley	Not present
Oats	Not present
Spelt	Not present
Sesame	May contain traces
Soya	Contains
Milk	Not present
Eggs	Contains
Fish	Contains
Crustaceans	Not present
Molluscs	Not present
Peanuts	Not present
Tree nuts	Not present
Celery	Not present
Mustard	Contains
Lupin	Not present
Sulphites	Not present

Contains = declared as an ingredient. May contain traces = Subway’s suppliers say the allergen is present at the manufacturing site and there is a significant risk of cross-contamination. Subway publishes allergens by ingredient, not by finished item, so Boone builds this table from Italian White bread, the filling, and onion, cucumber and lettuce. Choosing a different bread, cheese or sauce changes the allergens. Food is freshly prepared in Subway kitchens where many allergens are handled, so Subway cannot guarantee any item is allergen free. Vegan items are made to vegan recipes but are not suitable for people with milk or egg allergies.

Frequently asked questions

How many calories are in a Subway Tuna Mayo Footlong Sub?+

Boone calculates that a Subway Tuna Mayo Footlong Sub contains 800 kcal, which is 40% of an adult’s 2,000 kcal daily reference intake and 62% of the daily intake for a child aged 4 to 6.

How much sugar is in a Subway Tuna Mayo Footlong Sub?+

A Subway Tuna Mayo Footlong Sub contains 13.2g of sugar, of which Boone estimates 11.4g is free sugar, or about 2.9 teaspoons. That is 38% of an adult’s 30g daily limit and 60% of the 19g limit for a child aged 4 to 6.

How much saturated fat is in a Subway Tuna Mayo Footlong Sub?+

A Subway Tuna Mayo Footlong Sub contains 6.8g of saturated fat. Boone calculates this as 34% of the daily guideline for an adult woman and 23% for an adult man, because the guideline differs by sex: 20g and 30g.

How much salt is in a Subway Tuna Mayo Footlong Sub?+

A Subway Tuna Mayo Footlong Sub contains 3.6g of salt. Boone calculates that as 120% of the daily limit for a child aged 4 to 6 and 60% of an adult’s 6g limit.

Does the Tuna Mayo Footlong Sub figure include cheese and sauce?+

No. Subway calculates it on Italian White bread, the filling, and onion, cucumber and lettuce only. A portion of grated mozzarella and cheddar adds 45 kcal. A 14g portion of sauce adds between 14 kcal for tomato ketchup and 80 kcal for garlic and herb.

Is a footlong Tuna Mayo just double a 6 inch?+

Yes. Subway’s footlong figures are its 6 inch figures doubled, so a Subway Tuna Mayo Footlong Sub has twice the calories, sugar, salt and saturated fat of the 6 inch version: 800 kcal against 400 kcal.

Is a Subway Tuna Mayo Footlong Sub ultra-processed?+

Subway does not publish ingredient lists for food made to order, and UK law does not require it to, so Boone cannot assign a NOVA group to this item.

Is a Subway Tuna Mayo Footlong Sub classed as less healthy?+

Under the government’s 2018 nutrient profiling model a Subway Tuna Mayo Footlong Sub scores 4. The model classes a food scoring 4 or more as less healthy, so this item would be. The 2018 model is published but not yet used for advertising rules. Subway publishes fibre, so Boone uses its figure.