For parents: Can one of you afford to stay home?

``I have to work. We need the money.'' The refrain of the working parent rings true after every bill-paying session, when the money they were hoping to use for dance lessons for their tot or a night out for themselves somehow gets gobbled up by mortgages, utilities, child care....

``For many parents today, things start to possess them,'' says Connie Drapeau, a financial consultant and vice-president at Merrill Lynch & Co. ``They buy a big house with a big mortgage, and the house owns them - they both have to go to work to pay for it.''

Instead, she advocates building ``a life style that gives you choices - so working when you have kids is your choice, not your mortgage's choice.''

For anyone who's ever wondered, ``Do I really have to work?'' there are ways to find out. First, figure out how much of your earnings go toward working. What kinds of expenses would be immediately cut if you stayed home - taxes? child care? working clothes?

Mary Anne Lerch, a financial analyst and mother of three, calculated the following work-related expenses for a mother of two young children in day care, earning $18,000. Her figures are for one hypothetical family. Individual circumstances and priorities, of course, would vary widely:

Taxes at 27 percent (joint return): $4,860.

Child care at $75 a week per child for 50 weeks (minus two weeks' vacation): $7,500.

Transportation ($20 a week on the subway, savings of at least $10 a week for 50 weeks): $500.

Lunches, $5 a day: $1,250.

Clothes: $500 per adult plus $100 per child annually, reduced by careful shopping and more laundry to $100 per adult plus $50 per child: $400. This, clearly, can happen only when you frequent thrift stores and select hand-me-downs. And it's much easier if kids are young.

``Guilt presents'' (Mrs. Lerch buys these on her way home, spending at least $10 per week): $500.

Dinners out, at $50 a week for two to three dinners: $2,500. This sounds like a lot, but a family of four, with fairly big eaters, can easily spend $40 to $50 simply going to a fast-food outlet twice a week.

Bottom line of money earned: $490.

Your work-related expenses may be different - you may eat out more, buy fewer ``guilt presents,'' or feel you need to join a professional group and attend its monthly dinners. Whatever the category, try to get a price for any expense directly related to your working.

Next, figure out places you can save. ``What you lose by working is time,'' says Mrs. Lerch, ``and that makes every single thing you buy more expensive. I even bought the very first car I drove at the lot. I didn't have time to shop.''

By careful shopping, looking into thrift stores, meandering through garage sales, and - in the case of hurried meals grabbed at fast-food joints - simply doing without, you can cut one- to two-thirds off many budgeted areas.

Mrs. Drapeau suggests you begin by ``getting a handle on just how much it costs you to live the way you're living - what do you need every month to get by?''

By going through the last six months' check stubs and keeping track of what you spend for a month or so, you should get a rough idea of what's gobbling the dollars. Then, look at each budget area to see which would be easiest to cut. Clothing is a good place to start - you don't need new suits to take care of a baby, and the clothes you have now may tide you over for a year or two.

Food is another big area to cut. Going out to eat once a month to an inexpensive restaurant - instead of the two to five times a week we're told is typical of two-income families - results in big savings. Having the time to do comparison shopping at the grocery store can also boost the family budget in a big way.

Once you've made cuts in these and other obvious areas - cleaning help, health club memberships, expensive hobbies, big-money entertainment, vacations via airplanes - as well as cutting out items on the list you made of your work-related expenses, see how far you are from being able to meet your budget with one income. If the gap's still wide, and you still want to leap it, consider the big-ticket items: mortgages, private schools, automobiles.

Could you live in a smaller or less expensive home? (For some, the question is - do they make a less expensive house?) Counting any extra commuting costs and the one-time expenses of moving (and selling your present home, if you own it), how much would you save in mortgage and home insurance costs?

If you were home and able to work closely with your child's school, could he get a good education through the public system? If you own a fairly expensive car, could you sell it and pay cash for a used model? That would save you both the car payment and some dollars in car insurance.

None of these changes are easy, since they involve fundamental changes in life style. And making them may still not bring you close to your minimum budget. But if they do - if you find you are comfortable with making changes that put you within $1,000 to $2,000 of that minimum - you'll find yourself with a number of choices.

You can continue to work outside the home and provide the family with both basics and luxuries. You can look for a way to use your skills at home to generate $1,000 or more annually. You and your spouse could both scale back in hours (if employers are willing) and spend more time with your children. Or you can go home and make deep, fundamental cuts (giving up things like the telephone, or meat), and tell yourself it's only a temporary measure. The choice is yours.