Americans' view of estate taxes is highly ambivalent.

On the one hand, we generally approve of the proposition that a person should be able to build a business or other enterprise and pass it on to his or her children. We recognize that building for the future, particularly our offspring's future, is one of the motivational engines of our economic system.

On the other hand, when we see the rich family's son zooming into the high school parking lot in a $50,000 car, we grind our teeth and mumble "there ought to be a law."

And so there is a law, a whole collection of them actually, taxing "gratuitous transfers" of wealth. The most important of these for most people cover gifts and estates, and the two are almost always considered together since the taxation of gifts and estates is unified.

The ambivalence shows up this way. First, anyone may give anyone else $10,000 a year without tax to either party. Second, everyone (except some non-U.S. citizens) has an automatic credit of $192,800 against any federal estate taxes that may be due at the time of death.

This is enough to offset tax on an estate worth less than $600,000. Also, one spouse may leave any amount to the other spouse without tax.

Thus, as a practical matter, most Americans do not need to worry about estate taxes because the credit will protect them.

But rising property values during the 1980s pushed many people toward that cutoff. Real estate values, though slumping now, rose enough to propel even modest-size homes well into six figures. For couples with a successful stock portfolio and a big life insurance policy, the appreciation often pushed an estate past $600,000 and into tax brackets of up to 55 percent.

"The point is that even people living a fairly modest life can get clipped very unnecessarily, said Karen P. Schaeffer of Schaeffer Financial of Bethesda.

This work sheet, supplied by Schaeffer Financial of Bethesda, is meant to help you get an idea on whether estate taxes are a worry for you. Like other work sheets in this guide, it does not purport to give you an exact reading on your tax liability.

The first step is to calculate the value of your gross estate. This consists of 100 percent of everything you own and 50 percent of everything you own jointly with your spouse. The value should be the fair market value as close as you can determine it. Include any assets held in a revocable living trust and the death benefit of any insurance policies owned by you or on your life and payable to your estate.

Next, subtract expenses likely to be incurred by your estate, such as your funeral and lawyer's fees. These expenses must be reasonable, however. Costs vary, with different state imposing different rules and are difficult to generalize. But Schaeffer suggested using 6 percent of the estate as an approximation.

Subtract debts you owe, including mortgages, consumer loans and unpaid taxes.

Now subtract deductions. First, anything left to a spouse is 100 percent deductible as long as it is left with no strings attached. If you contemplate leaving assets in trust to your spouse, they may qualify for the marital deduction, but you need the help of an attorney to make sure.

There is an important exception to this rule. If the surviving spouse is not a U.S. citizen, he or she does not qualify for the marital deduction. Schaeffer noted that this rule sometimes catches people by surprise.

Second, if you are planning to leave anything to charity, that amount is deductible as long as there are no strings attached to the gift.

Next, Step 4, add back any taxable gifts you have made during your lifetime. For example, if you gave one person more than $10,000 during a single year, the amount over $10,000 should be added here. When you have done that, the total is your taxable estate.

Now you can figure your estate tax using the table on this page. The table works the same way as the one in a standard income tax return. Find the numbers that bracket you taxable estate. Take the value from the column headed "tax on Column 1." The subtract column 1 from your taxable estate and multiply the excess by the percentage in the column headed "rate on excess." That is the tax you owe.

Remember, this approximation may change over time.

There are many strategies to reduce the burden of estate taxes. Different kinds of trusts provide various benefits, as can gifts to heirs and charitable contributions. In some cases, such as irrevocable trusts, if you do it wrong, you can end up losing control of the assets and still having them included in your taxable estate.