Actually, the maximum amount of life insurance coverage you may purchase depends on your budget, and how much the insurance carrier is willing to insure you for.
Some insurers may offer up to 10-20 times your annual income in life insurance protection.
However, the insurance company usually asks the total amount of life insurance you already own, when you apply for a policy.
The insurer doesn't want you to be over-insured, because life insurance does pay out a death benefit for suicide, if it occurs more than 2 years after you buy your policy (one year in some states).
Learn more about how much life insurance you can buy.