What the KitchenAid KDTM405P*** costs to run
The KitchenAid KDTM405P*** is certified by ENERGY STAR at 240 kWh a year, about average for its category to run among dishwashers currently certified.
That $45 is priced at 18.8¢/kWh, the average of all 51 state rates this site tracks. Your own state's rate is one click away.
Efficient, or not, for a dishwasher
The category average is 232 kWh/yr; this model runs 3.4% above it, ranking 623 of 737 dishwashers tracked here for running cost. That average is drawn from all 737 dishwashers ENERGY STAR currently certifies, not an outside number, a $2/year gap from this model at the national rate. Full sourcing is in the sourcing notes.
Right next to it on the list
A rank or two either side of the KitchenAid KDTM405P***: KitchenAid KDTF924PPS ($45/yr, 240 kWh/yr), then KitchenAid KDTS224S*** ($45/yr, 240 kWh/yr).
Within the KitchenAid lineup
Ranked 9 of KitchenAid's 14 certified dishwashers, this sits between the KDFS224S*** ($45/yr, the brand's cheapest) and the KDTS434S*** ($45/yr, its priciest).
KitchenAid KDTM405P*** over 9 years
NAHB's Study of Life Expectancy of Home Components puts a typical dishwasher's service life at 9 years; run the KitchenAid KDTM405P*** that long and it costs about $406 in electricity, on top of whatever it cost to buy.
Weighing a replacement
Efficient as certified dishwashers go, $45/year is a reasonable baseline if you're comparing what else is on the market.
Worth comparing a few current certified models before deciding.
If you're keeping it
The KitchenAid KDTM405P*** already costs $45/year to run; a repair bill on top of that is the kind of expense a protection plan exists to smooth out.
Where this number comes from
The full Dishwasher category page shows all 737 dishwashers ranked by cost; the state-rate guide covers the half of this number that isn't the appliance. The 240 kWh/yr figure is ENERGY STAR's own certification, not a wattage estimate; exact dataset IDs are on the data sources page.