37% of Americans with children under age 18 do not have any life insurance, according to a new Bankrate.com study. And about one-third of the parents who do have life insurance have no more than $100,000 of protection.

"These numbers mean that over 20 million households with dependent children either don't have any life insurance or don't have nearly enough," said Doug Whiteman, Bankrate.com's insurance analyst.

• Overall, 42% of Americans lack life insurance and about half of those who have it are covered for $100,000 or less. 
• Even 1 in 4 insured people with annual household income of $75,000+ have $100,000 or less in coverage. 
• 11% of women and 5% of men say they have life insurance, but they don't know how much.

"There are many rules of thumb regarding how much life insurance is enough," Whiteman said. "Ultimately, it's a personal decision that's based on a range of factors including your debts, mortgage, potential college costs for your children (that's if you have any), and likely burial expenses. Bankrate has a great life insurance calculator to help you come up with the right amount."

The survey was conducted by Princeton Survey Research Associates International (PSRAI) and can be seen in its entirety here:

http://www.bankrate.com/finance/insurance/money-pulse-0715.aspx