Model
Danby DDW621WDB
Rank #11 means 10 of the 709 dishwasher models we track cost less to run each year; the 13th efficiency percentile means it uses less energy for its size than 13% of those models.
What does the Danby DDW621WDB cost to run per year?
At $29 a year to run, the Danby DDW621WDB is one of the very cheapest dishwasher models we track, ranking #11 of 709, in the bottom five percent on cost. It uses 30.2% less energy than the U.S. federal standard model in its class, which would cost about $41/yr to run, a saving of roughly $12 a year. Once capacity is factored in, its efficiency percentile of 13 is among the lowest in its class. At 6 place settings, it is a small dishwasher for the class, which runs 2 to 18 place settings; size and efficiency are the two levers behind the figure above, and this dataset does not carry a separate efficiency-factor column for this class.
Immediately around it on the leaderboard, the Comfee CDC22P**** at $29/yr runs a little cheaper and the Danby DDW631SDB at $29/yr runs a little more, a sense of how tightly models are packed at this point in the ranking. A dishwasher typically stays in service for somewhere around 9 years; over that span, the Danby DDW621WDB's $29/yr adds up to roughly $261 in electricity alone, before purchase price or repairs.
Also sold as: Black+Decker BCD6W.
By the numbers
The Danby DDW621WDB normalized against its whole class, so each figure means something.
What it costs you over time
Running cost is an every-year number, so it compounds. At $29/yr, here is what the Danby DDW621WDB adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Danby DDW621WDB costs about $290. That is roughly $120 less than a standard model in its class, which would run closer to $410 over the same ten years.
How the Danby DDW621WDB compares
The dishwasher class we track runs from $15 to $45 a year. At $29/yr, it runs about $15 a year cheaper than the class median of $44, and it is about $14 a year more than the cheapest dishwasher to run at $15. Against the US federal standard model for its class at about $41/yr, the Danby DDW621WDB uses 30.2% less energy.
What drives its running cost
At 6 place settings, the Danby DDW621WDB is a small dishwasher for its class, which spans 2 to 18 place settings with a median of 14 place settings, less capacity to service is usually the first reason a running-cost figure lands on the low side, before efficiency even enters the picture.
- Place-setting capacity. A larger dishwasher heats more water per cycle, so bigger capacity generally means a higher annual energy figure, independent of how efficient the unit is.
- Water heating. The booster heater that brings water up to sanitizing temperature is usually the single largest electrical load in a dishwasher's cycle.
- Cycle length and drying method. Cycle selection, eco versus heavy, air-dry versus heated-dry, moves real running cost more than most owners realize for a given capacity.
Common questions
Is the Danby DDW621WDB cheap to run?
Yes, relatively. At $29 a year it ranks #11 of 709 dishwasher models we track, in the cheaper part of its class to run.
How much does the Danby DDW621WDB cost per month?
Roughly $2.4/mo, spreading the $29/yr estimate evenly across twelve months at $0.1856/kWh. Actual monthly bills swing with your rate and usage pattern.
How is this running-cost figure calculated?
We take the model's published annual energy use of 155 kWh from ENERGY STAR and multiply it by the US average residential electricity rate of $0.1856/kWh, giving about $29 a year. It is an electricity-only estimate and does not include purchase price, water, or installation.
How efficient is the Danby DDW621WDB for its size?
13th percentile once size is factored in. That means its size-adjusted efficiency is not the main reason for the running-cost figure above; its capacity plays a large role too.
Cheaper to run in the same class
Source
ES_0092264_DDW621WDB_05292023110806_80164647View certified dishwasher listingsENERGY STAR data as of July 2026Danby and DDW621WDB are used here for identification only and are not endorsements. Figures are computed by WattWise Labs from public ENERGY STAR data, not measured in our own lab.