Last Update: 28 February 2023
You decided on a 4% withdrawal strategy and implemented the Bogleheads Three Funds Portfolio: how likely, so far, your investment would have been enough for your retirement?.
In this post, we will simulate different retirement timeframes and check the sustainability of the withdrawal rate, using actual historical series.
Success Rate of a 4% Withdrawal Strategy
Let's calculate the success rate of a 4% Withdrawal Strategy, on the Bogleheads Three Funds Portfolio. Would you have also saved a portion of your invested capital, at the end of your retirement?
As usual, the withdrawal is expressed as a yearly rate and refers to the initial capital. After that, the withdrawal amount is monthly adjusted for inflation.
For instance, assuming a 20 years retirement, the algorithm will cover each 20 year timeframe starting at every possible month in the given period between the start and end month.
Here's how simulations work (each simulation is based on actual asset class returns, in US dollars):
 At the beginning, you start with a certain amount of money invested in the portfolio (i.e. the initial invested capital).
 Each month, money is withdrawn from the portfolio. The withdrawal rate is calculated based on the initial withdrawn, annualized.
 Each month, portfolio value is updated, based on the asset classes returns (dividends are supposed to be reinvested).
 Each month, portfolio is rebalanced, to reset to the original weight of the assets (applicable only if portfolio contains at least 2 assets).
 Each month, the withdrawal is adjusted for inflation (US Inflation is used for simulation).
The Perpetual Withdrawal Rate (PWR) is the percentage of the initial portfolio balance that can be withdrawn at the beginning of each month with inflation adjustment, preserving the original invested capital, adjusted for inflation too. In this website, you can find PWRs with 100% Capital Protection, or less.
The Safe Withdrawal Rate (SWR) is the percentage of the initial portfolio balance that can be withdrawn at the beginning of each month with inflation adjustment, without the portfolio running out of money. In this website, you can find SWRs with 100% Success rate, or less.
Learn more about Withdrawal Rate simulation
Data Sources and Credits
We are calculating the success rate over all the past Nyear timeframes, on actual historical data, also focusing on how much capital (inflation adjusted) will remain after the retirement.
4% Withdrawal Rate 
% Success



20 Years  30 Years  
Success Rate (%) 
100.00

100.00

Fail Rate(%) 
0.00

0.00

Preserved Capital (infl. adj.)  % Success, on % Preserved Capital  
At least 0% 
100.00

100.00

At least 25% 
100.00

100.00

At least 50% 
98.89

100.00

At least 75% 
92.24

99.17

At least 100% 
86.43

98.76

4% vs Perpetual/Safe Withdrawal Rates
Let's compare a 4% withdrawal with the Safe and Perpetual Withdrawal Rates, over different timeframes.
In the table below, the guaranteed thresholds of Success/Preserved Capital are highlighted in green, elsewhere in red. To review a specific timeframe for this portfolio, click on the links in the table.
PWR (%)  Perpetual Withdrawal Rate

SWR (%)  Safe Withdrawal Rate



Preserved Capital  100%  75%  50%  25%  0%  0%  0%  0%  0%  
Success Rate  100%  100%  100%  100%  100%  95%  90%  80%  50%  
Timeframes 
20 Years Worst Period (from) 
1.945 Apr 2000 
2.770 Apr 2000 
3.594 Apr 2000 
4.419 Apr 2000 
5.243 Apr 2000 
5.877  6.170  7.325  8.537  
30 Years Worst Period (from) 
3.581 Mar 1973 
3.908 Mar 1973 
4.234 Mar 1973 
4.561 Mar 1973 
4.887 Mar 1973 
5.953  6.256  6.722  7.576 
Related Pages
Portfolio Main Page:
Bogleheads Three Funds Portfolio
For the Bogleheads Three Funds Portfolio, we have prepared a report for each available timeframe:
20Year
30Year
if you want to learn more about the statistics of a specific withdrawal rate, we suggest these in particular:
2%
2.5%
3%
3.5%
4%
4.5%
5%
Website Homepage:
BestRetirementPortfolio.com