Cost to run a hot tub: the honest monthly figure

Nobody regrets buying a hot tub like they regret heating one. The honest running-cost answer: a well-insulated modern tub costs roughly 25-50 a month in use, an older or poorly-insulated one in a cold climate can pass 90, and a lightly-used summer-only tub lands far below - wide ranges because climate, electricity price and habits swing the number more than the tub does. The electricity cost calculator prices your own rate against the components below.

Where the money goes

The heater (typically 2-3 kW) is the headline, but it mostly replenishes losses: a well-insulated tub in mild weather heats an hour a day; a windy-deck tub at freezing temperatures can heat six. The circulation pump runs nearly continuously on many models (150-300 W - a real base-load line, the same arithmetic as the standby audit). The jets (1-3 kW) cost pennies per soak. Add the water-treatment chemicals and the odd filter, and the true monthly figure is electricity plus a modest extras line.

The habits that halve it

Keep the cover on and the cover good - a waterlogged, sagging cover is the number one cost multiplier; heat escapes through it like an open window. Hold 37-38 C rather than hotter - every degree adds standing cost. Windbreak the tub (fence, hedge, spa enclosure) - wind strips heat from a cover faster than cold does. Check the tariff: heating overnight on an off-peak plan where the tub tolerates it suits the time-of-use logic. And in long absences, draining and shutting down beats heating an empty tub for nobody.

Before you buy one

Ask the seller for the heater wattage, the circulation pump's draw and an honest estimate of daily heating hours in your climate - those three numbers times your rate is the real cost of ownership, and the difference between tubs is bigger than the difference between price tags. The running cost, not the sticker, decides whether a hot tub is a luxury you use or a bill you resent.