The conversion option should be only 5% extra on term assurance policies, however some companies will charge more. It will allow you to continue on cover usually up to age 80, however the longer you leave it to convert, the more expensive the premium will be. You will be charged the normal rate for a person of your age 'at the time of conversion'. To get an idea of potential cost, you could get quotes for the level of cover you have chosen for someone say age 50, 55 and 60 today, and chose a term of 5, 10 or 15 years. This will give you an idea of cost however rates will inevitably change over this period to some degree. It might be worth it if potentially you have medical problems down the line which could cut your life expectancy. In this instance you could pay normal rates for a higher, or even uninsurable, risk.