Yes I probably should have been more precise. The ARB is not a loss it is a reduction in what you get per year but you get it for a year longer - which is why there will be a 'break-even' point. Before this point you are 'ahead' and after it you are 'behind' but in all reality if you have worked out that you can survive on the 'before' figure it's probably academic. The reduction factors for the final salary are: 1 year: 0.956 (4.4%) 2 years: 0.912 (8.8%) 3 years: 0.871 (12.9%) 4 years: 0.833 (16.7%) 5 years: 0.796 (20.4%) In planning I always take a more pessimistic view so rounded the reductions up rather than down. Looking in real numbers my wife's pension goes from £21,500 to £17,000 a reduction of 4,500 but she misses out on 5 x £17,000. She gets 3 lots of the difference back through the tax-free lump sum and with tax differences etc I did work out it was 13.8 years to hit the break even point.