Where the 4% Rule Came From
The 4% rule originated from William Bengen's 1994 research published in the Journal of Financial Planning. Bengen backtested historical US market and inflation data and found that a retiree withdrawing 4% of their initial portfolio annually โ adjusted for inflation each year โ would not have run out of money over any 30-year period from 1926 to 1994.
It was a powerful finding. It gave retirees a simple, memorable framework: save 25ร your annual expenses, withdraw 4%, and you're set. For many years, it held up.
The problem is that the conditions that made the 4% rule robust โ particularly the bond yields of the 1980s and 90s and the US equity returns of the 1990s bull market โ no longer reliably exist in the same form. And critically for Canadians: the original research was based entirely on US data, using the S&P 500 and US Treasury bonds. Canadian portfolios, with their heavier weighting toward financials, energy, and the TSX, behave differently.
Why It Fails in 23% of Scenarios
The 4% rule's biggest vulnerability is sequence-of-returns risk: the catastrophic impact of experiencing a significant market downturn in the first 5โ7 years of retirement. It doesn't matter how well markets perform in years 15โ30 if you've been forced to sell assets at depressed prices in years 1โ5.
Two retirees, same $1M portfolio, same 4% withdrawal rate, same average return of 6.5% over 30 years. Retiree A experiences negative returns in years 1โ5. Retiree B experiences the same negative returns in years 20โ25. After 30 years: Retiree A has $0. Retiree B has $1.4M. Same returns. Completely different outcomes.
Modern research from the Canadian Institute of Financial Planners and academic updates to Bengen's original work (Pfau, 2021; Kitces, 2022) put the truly safe withdrawal rate for a 60/40 Canadian portfolio in 2025 market conditions at 3.5%โ3.8% for a 30-year horizon.
| Portfolio ($) | 4% Annual Withdrawal | 3.7% Annual Withdrawal | Difference | 30-yr Survival Rate (3.7%) |
|---|---|---|---|---|
| $500,000 | $20,000/yr | $18,500/yr | -$1,500/yr | 91% |
| $750,000 | $30,000/yr | $27,750/yr | -$2,250/yr | 91% |
| $1,000,000 | $40,000/yr | $37,000/yr | -$3,000/yr | 91% |
| $1,500,000 | $60,000/yr | $55,500/yr | -$4,500/yr | 91% |
| $2,000,000 | $80,000/yr | $74,000/yr | -$6,000/yr | 91% |
The gap looks uncomfortable. Who wants to give up $3,000โ$6,000 per year in retirement income? The answer: nobody. Which is why the 3.7% rate alone isn't the solution โ the full strategy framework below is.
The 3.7% Strategy: How It Works
The insight that makes the 3.7% rate work without a significant lifestyle sacrifice is this: your portfolio withdrawal rate isn't your only income source in retirement. Most Canadians have CPP, OAS, and potentially a pension. The strategy is to integrate these sources intelligently to reduce portfolio dependency in the early years โ exactly when sequence risk is highest.
Delay CPP to 70 if possible
CPP increases 8.4% per year of deferral past 65 โ a guaranteed return that no market investment can reliably match. From age 65 to 70, that's a 42% permanent increase in monthly income for life. For a couple, the lifetime value of this delay over 25 years of retirement can exceed $184,000. Bridge the CPP gap with RRSP/RRIF withdrawals at lower marginal rates in your early 60s.
Bucket your portfolio into 3 time zones
Bucket 1 (Years 1โ3): 2โ3 years of living expenses in cash or GICs. Never touched by market volatility. Bucket 2 (Years 4โ10): Short-to-medium bonds and balanced funds. Replenishes Bucket 1. Bucket 3 (Years 10+): Full equity growth portfolio โ the engine. This structure means you never need to sell equities when they're down. Sequence risk is neutralized.
Front-load RRIF withdrawals before OAS at 65
Between ages 60โ65 (before OAS), withdraw from RRSP/RRIF at lower marginal rates while income is relatively lower. This "RRIF melt" strategy reduces future mandatory minimum withdrawals, potentially lowers OAS clawback risk at 75โ80, and produces tax savings of $15Kโ$40K over a decade for many retirees.
Apply dynamic withdrawal rates, not fixed
The 4% rule is static โ it doesn't respond to market conditions. The 3.7% strategy uses guardrails: if your portfolio drops more than 20% from its retirement-day value, reduce withdrawals by 10% temporarily. If it grows more than 30%, you can increase withdrawals. This self-correcting mechanism maintains portfolio survival rates above 95% across virtually all historical market scenarios.
The Canadian Context: CPP + OAS Changes Everything
Most 4% rule research was designed for Americans with Social Security. Canada's CPP and OAS system โ particularly after the CPP enhancement that began in 2019 โ is more generous than many retirees realize when optimized. A couple both taking enhanced CPP at 70 in 2025 could receive $3,800โ$5,200/month combined before OAS. At 65, add $1,468/month combined in OAS (2025 rate).
This CPP+OAS floor changes the calculation fundamentally. If your monthly living expenses are $6,500 and your CPP+OAS provides $5,500, your portfolio only needs to generate $1,000/month โ a 1.2% withdrawal rate on a $1M portfolio. The sequence-of-returns risk on a 1.2% withdrawal rate is negligible.
Canadians who optimize their CPP/OAS timing and integrate it with their RRIF withdrawal strategy can often sustain a significantly higher lifestyle in retirement than the 3.7% rule alone suggests โ because their portfolio withdrawal rate can be much lower than 3.7% once CPP/OAS income is accounted for.
The Bottom Line
The 4% rule served a generation of retirees well. But it was designed for a different era, different market conditions, and a US-centric context. Applied rigidly to a Canadian retiree in 2025 โ without accounting for sequence-of-returns risk, CPP/OAS optimization, or RRIF timing โ it carries a meaningful failure rate.
The 3.7% strategy isn't just a number adjustment. It's a framework that integrates all the income sources available to Canadian retirees โ CPP, OAS, RRIF, TFSA, and portfolio withdrawals โ into a system designed to survive any 30-year market scenario while maintaining a comfortable lifestyle.
The goal isn't to spend as little as possible in retirement. It's to spend confidently, knowing the math works for as long as you need it to.