Financial planning for retirement includes a minimum of three steps. And the steps are the same regardless of your personal circumstances: married or single, childless or with a large family, upper-income or struggling to get along.

The first step is to estimate your post-retirement needs. Some experts on retirement finances relate this estimate to your preretirement income, setting up guidelines like "two-thirds" or 70 percent" of your take-home pay before retiring.

This may be fine for macroeconomic planning. But when it comes down to the individual, this step is really no more than a guessing game, involving the kind of life you hope to lead after retirement and the number of dollrs you expect it will require.

Don't be discouraged by the likelihood that your retirement plans will change several times during the years before you get there. This is an exercise that must be repeated periodically -- you'll have ample opportunity to modify your plans as time passes.

Trying to predict the course of inflation over the next 20 years is likely to prove futile. Instead, use current dollars for both estimated needs and estimated income, in the hope that they will stay in step with each other.

When we talk about investment programs, we'll discuss ways to protect some of your funds against the erosionary impact of inflation.

After you've made your best estimate of how much money (in terms of 1980 dollars) you'll want when you retire, start listing known sources of retirement income.

This list could include social security, company or government pensions, IRA or Keogh plans, insurance annuties and any long-term savings or investments already accumulated that are not earmarked for other needs -- like children's college costs -- before retirement.

If you own your home and your life-style planning contemplates its sale at retirement, include a conservative estimate of the net proceeds from such a sale (gross price reduced by selling expenses and mortgage balance).

Now compare the two numbers: what you expect to need, and what is already provided for in one form or another. If your anticipated income is greater than or at least equal to your projected needs, then you're home free. You need only protect your present assets and perhaps build a little cushion.

But it you won't have enough to provide the kind of retirement life-style you would like, then the message is obvious. In the intervening years between now and retirement, you will have to accumulate enough additional capital to cover the shortfall.

Don't expect outside help. Existing pension plans are not likely to be sweetened beyond present levels. Business emphasis, in the near future at least, is likely to be on increasing productivity and retirement pay as a cost of doing business is a non-productive expense.

Despite all the scare talk, social security is expected to be around (and solvent) for quite a while. But the trend is apt to be to reduce -- or at least hold the line on -- benefits. You have to figure that, except for cost-of-living increases, what you see is what you'll get.

So this is likely to be a do-it-yourself project. It may be unpopular in some quarters to say so, but I find nothing wrong with the concept of self-help. Society's programs should provide an income sufficient to insure a basic living standard -- but if you want something better than that, you're on your own.