Planning for retirement – for most people – hinges on projections that show the size of the nest egg at specific ages. Maybe you can retire earlier than you thought, maybe not. But if the projection tool you're using is incorrect, you could be in a spot of bother.

That's what has happened at a major superannuation fund, which has apologised to members.

The Financial Standard reports that members of Media Super received an apology after it was discovered the information underpinning its benefit projection tool had not been updated since 2015.

The Standard writes: "Media Super's Retirement Income Simulator was made available on its public website in mid-2014 and its information later used in 2018 to provide estimated retirement balances to members on their private site.

"A generic calculator, the tool estimates projected super balances and how long a balance may last based on, among other things, assumed administration fees, insurance premiums and investment returns."

The apology explained that in September 2021 the fund realised that the fees, premiums and returns used by the tool on the public website were last updated in 2015.

The errors were fixed in late October 2021.

"It's important to note that this error in no way affects members' account balances, nor has any financial impact on your account, so there's nothing you need to do," Media Super told members. "The purpose of the calculator is only to provide an estimate of your super account balance at the time of retirement and does not impact your actual account balance.

"Media Super is committed to ensuring these types of errors don't occur again."

Do you trust these projection tools? Do you use more than one just in case?