A standard mini fridge can run up a bill anywhere from $27 a year to $80 a year, as of 2016. Month to month, the fridge can cost anywhere from approximately $2 to $7.
The cost of running a mini fridge varies depending on the fridge itself, including its make, model, and size in cubic feet. It can also be affected by the temperature of the fridge's environment; a warmer environment means the fridge uses more energy to stay cool, so the bill runs higher. A fridge that is put in a smaller space or one that is surrounded by other objects is also likely to run a higher bill because the surroundings trap heat.