Mars Bar Calories for UK Bar Sizes

How many calories in a Mars Bar depends on the bar serving size ...

There are 228 calories in a standard size Mars Bar, 151 calories in a Snacksize bar, 80 calories in a Funsize and 355 calories in a Duo pack. 

Calorie and Nutritional Information for a Standard Mars Bar

Serving Size 51g

| Source: WLR Food Database

A standard size bar contains 11.5% of reference intake/daily value of an average adult (2000 calories). Your calorie needs may be higher or lower.

Percentage of Calories from Each Macronutrient


  • 5% of calories are from Protein
  • 77% of calories are from Carbs
  • 18% of calories are from Fat

Calories in Alternative Serving Sizes

Funsize Mars (18g) 80
Snacksize Mars (33.8g) 151
Bar from Multipack (39.4g) 177
Standard Bar (51g) 228
Mars Duo Pack (78.8g) 355
1 Bar of Duo Pack (39.4g) 177

Nutritional Information per 100g

Other Nutrients

  • Vitamin A - 0
  • Vitamin C - 0
  • Calcium - 0
  • Iron - 0

Traffic Light Info for Mars Bars


Syn Values in Different Mars Bar Sizes

Using the calories divided by 20 formula gives 11.5 Syns for a standard serving size Mars Bar, 7.5 for a Snacksize and 4 for a Funsize.

Mars Bar Ingredients

Sugar, Glucose Syrup, Skimmed Milk Powder, Cocoa Butter, Cocoa Mass, Sunflower Oil, Milk Fat, Lactose and Protein from Whey (from Milk), Whey Powder (from Milk), Palm Fat, Fat Reduced Cocoa, Barley Malt Extract, Emulsifier (Soya Lecithin), Salt, Egg White Powder, Milk Protein, Natural Vanilla Extract, Milk Chocolate contains Milk Solids 14% minimum, Milk Chocolate contains Vegetable Fats in addition to Cocoa Butter

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