It really depends on your investment returns, since your young it's worth putting your money into higher risk scheme's that yield higher annual returns which is what's I've done for the last 5 years and my pension has averaged 14.4% ROI year on year, at that rate I can retire when I'm 56! Of course I don't expect that rate of return to continue but 7% over the life of pension isn't unreasonable IMO. The calculations you were probably looking at were based on 5%, that 2% difference may seem tiny but over the lifetime of a pension it can add up to a lot of money. Put this way if i retire in Dec-47 at 5% average growth my pension would be worth 528K (assuming consistent contributions), at 7% the same pension is worth 814K. That would mean the difference between an annual annuity of 26k and 41k or I could retire 5 years earlier with the same 26k a year annuity (maybe not as annuities are less if you retire younger).