There are many factors that affect the overall cost of owning an inflatable hot tub - electricity, water, filters, maintenance, disinfectants. The size of the hot tub will also determine the amount of water it will consume and how much time and power it will take to heat such a volume. The frequency of your use and how well you clean it add to how long it will last. In terms of the electricity bills, it depends on the area where you live.  We have gathered that around $600 a year is the average cost of running an average-sized standard inflatable hot tub. A larger one and more frequent use will lead to much higher expenses.