Question for you. On the calulator you provided, there are numbers included which I assume are from a previous deal you were working. Do you actually put 4 or 5k down on your leases? This never made sense to me when you could just do the lease with zero down and pay the same amount over time (keeping it in your bank account longer for interest). I do all of my leases with only the first payment due at signing.Whether you lease or buy is certainly a complicated calculation depending on how you look at all the angles and weight them to your particular needs. In my case a car is sort of a waste of money as I am mostly retired and don't drive all that much since the wife and I both have cars. The sensible thing would be to either have one car, or a dirt cheap one for me. But I like having a nice but reasonable car at my disposal so I'm willing to spend the money. I also like rolling them every 3 years since these days the tech (mostly) gets better every year and I never spend a dime on things like tires, batteries etc and the car is always under warranty. But that's just how I weight all the factors personally.
Here's a link to a spreadsheet I use when going into all the negotiations with the dealers that has proved helpful. The interesting thing about a lease is it's irrelevant what the car is actually priced at, only what it costs you out of pocket for the duration of the lease. If you punch in all the numbers for the down payment, monthly cost, your leased miles and few other factors it'll tell you what you're actually paying for the car for the duration of the lease. You can also enter in other data like how much extra miles cost if you go over your leased miles, or how many miles you think you'll use if it's under the leased miles so you can see what it actually will run you per mile, then you can do if/then comparisons.
Hope it might be useful.