A financial watchdog says people need to know more about how KiwiSaver accounts are performing and how much saving for retirement actually costs.
The Financial Markets Authority has launched a programme to help savers understand how hard their money is working.
Two-point-seven million New Zealanders are now in KiwiSaver.
But in the decade since its arrival many still haven't got to grips with how their money is being managed or how much it costs them in fees.
A new link on the FMA website tracks the performance of all KiwiSaver funds and what it means for savers once fund manger fees are deducted.
"We would like them to ask themselves, and if they want to their KiwiSaver provider, 'What am I getting in return for the fees that I'm paying you? Could I be paying the same fees and getting a better result in another one of your funds, or somewhere else?'" said Paul Gregory of the FMA.
The authority is not the only watchdog encouraging investors to learn more for better long-term gain, with potentially tens of thousands of dollars at stake.
Massey University banking expert Dr Claire Matthews says the Canstar website states that fees make a difference of $14,000 to $65,000.
"So there's sort of fifty-thousand dollars difference depending on what type of fund you're in."
The FMA says a graph on its site comparing fees with returns is one of the most popular with online viewers.