Model
Lg LDT780#**
Rank #305 means 304 of the 709 dishwasher models we track cost less to run each year; the 68th efficiency percentile means it uses less energy for its size than 68% of those models.
What does the Lg LDT780#** cost to run per year?
Among the 709 dishwasher models we track, the Lg LDT780#**'s $44/yr running cost ranks it #305, close to dead center. It uses 22.5% less energy than the U.S. federal standard model in its class, which would cost about $57/yr to run, a saving of roughly $13 a year. Its size-adjusted efficiency percentile of 68 is comfortably above the class median. This class has no published efficiency-factor figure beyond annual kWh itself, so at 15 place settings (the class spans 2 to 18), size is the clearest lever we can point to for this model's running cost.
Immediately around it on the leaderboard, the Lg LDPS676** at $44/yr runs a little cheaper and the Lg LDTH555** at $44/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 Lg LDT780#**'s $44/yr adds up to roughly $396 in electricity alone, before purchase price or repairs.
Also sold as: Lg SDWB24**.
By the numbers
The Lg LDT780#** 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 $44/yr, here is what the Lg LDT780#** adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Lg LDT780#** costs about $440. That is roughly $130 less than a standard model in its class, which would run closer to $570 over the same ten years.
How the Lg LDT780#** compares
The dishwasher class we track runs from $15 to $45 a year. At $44/yr, it sits right on the class median of $44, and it is about $29 a year more than the cheapest dishwasher to run at $15. Against the US federal standard model for its class at about $57/yr, the Lg LDT780#** uses 22.5% less energy.
What drives its running cost
At 15 place settings, the Lg LDT780#** is a mid-size dishwasher for its class, which spans 2 to 18 place settings with a median of 14 place settings, putting it squarely in the middle of the class on the size lever that drives most of the cost.
- Place-setting capacity. Place-setting capacity is the main driver of how much water a cycle has to heat, and heating that water is most of a dishwasher's electricity use.
- Water heating. Most dishwashers have a booster heater that raises incoming water to sanitizing temperature; this heating step, not the pump or motor, accounts for most of a cycle's electricity use.
- Cycle length and drying method. Heavy or sanitize cycles run longer and hotter than a normal or eco cycle, and heated-dry options cost more to run than air-dry or condensation drying.
Common questions
Is the Lg LDT780#** cheap to run?
Roughly, yes. Its $44/yr figure is close to the class median, ranking #305 of 709, neither a bargain nor a splurge on running cost.
How much does the Lg LDT780#** cost per month?
About $3.68 a month, which is the $44 annual estimate spread across twelve months at the US average rate of $0.1856/kWh. Your own bill scales with your local electricity rate and how heavily you use it.
How is this running-cost figure calculated?
The formula is annual kWh times price per kWh: 238 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $44 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Lg LDT780#** for its size?
68th percentile once size is factored in, a fairly typical result for the class.
Cheaper to run in the same class
| Rank | Model | Cost/yr |
|---|---|---|
| 300 | Lg LDPS676**15 place settings | $44 |
| 299 | Lg LDPN454**15 place settings | $44 |
| 298 | Lg LDPM676**15 place settings | $44 |
| 297 | Lg LDPH797**15 place settings | $44 |
| 296 | Lg LDPH676**15 place settings | $44 |
Source
ES_1118034_LDT780#**_06232023121509_80172922View certified dishwasher listingsENERGY STAR data as of July 2026Lg and LDT780#** 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.