First, determine how long you need or want your life insurance coverage. Even in your case though, is a 30 year policy going to be enough coverage?
You might be better off with a term life policy until age 65 or 70.
Regarding how long you need the term life coverage for, it's going to depend on what you want it to do for you.
What's the goal of your life insurance policy? How long until that goal is achieved?
Buy your life insurance with the premium guaranteed through the goal period. For example, if you need 20 year term life, make sure it is level term life insurance so the premium is guaranteed to remain the same each year for the 20 year term.
And read the fine print - that 30 year term, the premium is probably only guaranteed for 20 years. So, make sure to verify that with the insurance company or your agent.
Here's how you can learn more about how term life insurance works, and request your free, instant term life insurance quote comparisons online.