The Globe and Mail Content from: Fidelity iStockPhoto / Getty Images Realizing that they may end up retiring earlier than they had planned, 64 per cent of Canadians are worried they’re simply not saving enough, according to Fidelity Canada’s recent 2020 retirement survey . Figuring out whether you can afford to retire is a tricky process, because the staying power of your assets depends on so many assumptions and events. Will your cash flow in retirement be greater than your expenses? If you’re using the commonly accepted 70 per cent replacement rate – a rule of thumb that estimates what percentage of people’s pre-retirement income will be needed to maintain their future lifestyle – keep in mind that your expenses will vary throughout retirement.