Here I’ll do it fo you. I’ll use my current city, Lexington, KY as an example. Not a huge city, but well north of 300k inhabitants and the second highest cost of living in the state.
So we’re going to go with $2500 a month. That’s not an exact figure, but with full time hours at a wage of $20 that’s at least a fair number.
rent-$800 a month. There are certainly much cheaper apartments in Lexington, but $800 a month is a pretty decent apartment.
Car payment-$250 a month. I would guess that $250 a month gets you a pretty nice vehicle. I pay $297 a month for my BMW, so I would assume that $250 a month would get you a pretty decent car.
Car insurance-$130 a month? Now this would obviously depend on your driving history, but I think $130 is certainly a reasonable guess for what one would pay.
Utilities- $120 electric, this will be lower in the summer and obviously higher in the winter, but for an apartment I think this is a fair average payment for the year.
Water-$40. Most apartments these days will add your water bill to to your monthly rent payment. And in a lot of cases this will actually lower your payment as they divide the total amount they are charged by the water company by the number of tenants that they have. But again, we’ll go with $40.
Internet-$60? I can’t speak for everyone in Lexington but I pay $56 a month for internet only service through spectrum.
Cell phone-$110? That’s sounds reasonable for one line these days. That’s probably even a little high.
So using these numbers, you would still have almost $1000 a month left over for gas, healthcare, food, etc. So yes it’s pretty obvious that $20 an hour, in a decent size city, with a nice apartment and fairly nice car, is more than enough to live on.