anyone know which is cheaper?
We checked our water usage a few months ago and found that using the dishwasher vs. handwashing for us was about the same.
We checked the water meter, wrote down the number, ran the dishwasher (didn't let anyone use any water while the dishwasher was going) and found that our dishwasher uses 11 gallons of water to run. Then I hand washed dishes and found that I use about 3 gallons of water, handwashing, but have to do it 3 times a day, so I use about 9 gallons handwashing, sometimes a bit more, so to me, it is more convenient just to use the dishwasher, since it doesn't make much of a difference.
If you do check your meter to see how much water your using, you might need to convert the measurements. Our meter reads cubic feet, so I had to find a conversion site on the web to convert it to gallons, but it was easy enough to do!