You'll need at least $250,000 to help pay for child care and other expenses until your child is in middle or high school. Thinkstock By Kimberly Lankford, Contributing Editor From Kiplinger's Personal Finance, November 2014 My wife and I have a baby on the way. How much life insurance should we buy? My wife plans to work half-time while our child is young. --B.K., Washington, D.C.SEE ALSO: 10 Insurance Mistakes to Avoid To calculate how much life insurance you need, use this method recommended by Tim Maurer, a certified financial planner in Charleston, S.C. Each of you should add up the amount you’ll both need for funeral expenses, your mortgage and other debts. Include any education expenses you anticipate. For college, use current costs. Then calculate how much each of you would need to replace 50% of your current pretax earnings until retirement. To arrive at a lump sum, divide half your pretax income by 0.05, says Maurer. For instance, if you earn $100,000, divide $50,000 by 0.05, which equals $1 million. Add that to your mortgage, education and funeral-expense numbers for the amount of coverage you’ll need for yourself. Advertisement If the number your wife comes up with based on her part-time earnings is less than $250,000, get that much anyway, says Maurer. You’ll need at least $250,000 to help pay for child care and other expenses until your child is in middle or high school. If you plan to have more kids or anticipate other big expenses, bump the amount up to $500,000. Term life coverage doesn’t cost much. A healthy 30-year-old man can buy a 20-year, $500,000 policy for $244 per year; a woman would pay $214, says Byron Udell, CEO of AccuQuote.com. For $1 million in coverage, the man would pay $421 a year; the woman, $354 per year. If you plan to have more kids, consider a 30-year policy, for which the man would pay $704 for $1 million and the woman, $577. Got a question? Ask Kim at email@example.com.