You may not want to go out as much, travel as much , want new clothes, eat out as much and so forth.

o.t.o.h., medical and pharm. expenses will likely increase.

Any other variables I didn't think of?

65 or older are housing. Transportation, health care and food are next.

I was surprised as these expenses - housing, transportation and food can be controlled.

Agree about health care. One of the facts of aging, from my experience, is a weakened immune system that brings on newer health problems with more expensive treatments.

Fidelity estimates, for example, that a couple, both reaching age 65 in 2018 will need $280,000 over their lifetimes for OUT-OF-POCKET medical expenses ( https://www.cnbc.com/2018/04/27/how-to-plan-for-higher-health-care-costs-in-retirement.html ). They are both on Medicare, so this is medical costs above and beyond those paid for by Medicare.

Nor does the $280,000 include long-term care (e.g. nursing homes, assisted living facilities), and it doesn't include most dental, eye, or hearing care.

So lard up on your triple-tax advantaged Health Savings Accounts contributions -- same as a Roth IRA (no taxes on earnings or gains, no taxes on withdrawal) PLUS there is an up-front tax deduction. But withdrawals must be used for medical costs.

Our Long term insurance premiums alone are close to $10,000 a year. They have raised it recently.

And our premiums for supplemental insurance and dental are around $4500 a year.

ditto for any premiums paid for Medicare Advantage and for Part D drug plans.

My Medigap is a bit under $2500/year (for one individual, me)

Some yes, some no, as I recall from having looked into it a couple years ago...

It's how I've been thinking about my money for some years now.

I'm 71, and my income sources are:
Social Security
two annuities
a very small pension
what I take from my savings/investments.

The first three cover my basic expenses. The last takes care of various luxuries and things like travel.

I also have a long term care policy that's paid up, and even if I actually use up all of its benefit, there will still be a death benefit. Plus I have another decent life insurance policy.

So having $1 million may last more than 10 years if you spend $100,000 per year.

Medical expenses are the great unknown and could be devastating for many of us. In the USA that is especially so.

okay, at $1,000/month, that will last x months. How large that x is makes a difference.