The following popular investing and retirement planning tools have been developed by members of the Bogleheads forum.
Wiki link: Simba’s backtesting spreadsheet
The backtesting tool is a spreadsheet to backtest portfolio returns from 1970 to present [1985 to present if you want to include certain Sector/Tax-Exempt funds that started after 1985] of various Vanguard Mutual Funds. This tool is customizable and you can add the returns for any mutual fund.
The spreadsheet calculates various metrics such as CAGR/Std Dev/Sharpe Ratio/Sortino Ratio. The tools also provides rolling returns [both nominal and real] for 3, 5, 10 and 15 years. It lets you compare up to 5 different portfolios [both 1970-present and 1985-present
On-going discussion and support is in this Bogleheads® forum topic: Simba’s backtesting spreadsheet [a Bogleheads community project.
See also :
Site link: Portfolio charts
Many creative investors break the mold and build their own portfolios. These spreadsheets are designed for quick experimentation and can all be modified to study any asset allocation you wish.
On-going discussion and support is in this Bogleheads® forum topic: www.portfoliocharts.com … “The Coolest Portfolio Tool on the Web”?
Site link: Portfolio visualizer
Portfolio Visualizer provides online portfolio analysis tools for backtesting, Monte Carlo simulation, tactical asset allocation and optimization, and investment analysis tools for exploring factor regressions, correlations and efficient frontiers.
On-going discussion and support is in this Bogleheads® forum topic: [Back testing programs]
Site link: Excel Workbooks Available for Download
Bogleheads® forum discussion: Re: Ibond calculator
… an Excel spreadsheet that uses a macro to compute the values of each I Bond in a portfolio. It differs from the Savings Bond Calculator and Savings Bond Wizard in a couple of ways:
- Computes the values for twelve months at a time instead of only one.
- Works with any denomination; not just the ones that paper bonds were issued in.
Here is a sample screen shot:

The values agree with one row from my web pages that show the entire history of an I Bond. For example, the 12 values for the first bond listed above correspond to the year 2012 in $25 I Bond with 3.40% Fixed Rate Purchased September 1998.
Click the following link to open or download the Excel file: IBondPortfolioCalculator.XLS
Edit 8/10/12: … a couple of enhancements:
- Added an option to compute the Gain instead of the Value
- For each purchase added an Excel hyperlink to the value history page on my web site, http://eyebonds.info/ibon
Site link: Social Security Calculator
This site is designed to give individuals a clear idea of what their Social Security retirement benefits might be. It uses data provided by the Social Security website for an earning’s record. From that data, the site produces a detailed Social Security report.
What If?
This site provides clear interactive visuals that let the user investigate how different choices might affect their overall benefit. Scenarios include:
- What happens to my benefit if I earn additional wages for several more years?
- How does my benefit change as my total earnings grow during my lifetime?
- What happens if I choose to take my benefits early? What if I delay and take them late?
See also:
Bogleheads® forum topic: SocialSecurity.tools updated to include spousal benefits
Site link: Open Social Security
Open Social Security is a free, open-source Social Security strategy calculator. The tool is developed by Mike Piper, who blogs at Oblivious Investor.
The calculator runs the math for each possible claiming age (or, if you’re married, each possible combination of claiming ages) and reports back, telling you which strategy is expected to provide the most total spendable dollars over your lifetime.
Please note that this calculator should not be the only analysis you do, as there are various factors that it does not consider, such as:
- The fact that delaying benefits reduces longevity risk and therefore may be preferable even in some cases in which it is not the strategy that maximizes expected total spending, or
- Tax planning reasons or other unrelated reasons why it might be better for you to file earlier or later than the calculator suggests.
On-going discussion and support is in this Bogleheads® forum topic: “Open Social Security” calculator: feature requests, bug reports, etc
Wiki link: Variable percentage withdrawal
Variable percentage withdrawal (VPW) is a withdrawal method that adapts to the retiree’s retirement horizon, asset allocation, and portfolio returns during retirement. It combines the best ideas of the constant-dollar, constant-percentage, and 1/N withdrawal methods to allow the retiree to spend most of the portfolio using return-adjusted withdrawals. By adapting withdrawals to market returns, VPW will never prematurely deplete the portfolio.
The VPW method uses a variable (increasing) percentage to determine withdrawals from a portfolio during retirement. Each year, the withdrawal is determined by multiplying that year’s percentage by the current portfolio balance at the time of withdrawal.
The VPW method and spreadsheets were collaboratively developed and improved by a group of Bogleheads®.
The VPW Accumulation And Retirement Worksheet calculates variable portfolio contributions, during accumulation, and variable portfolio withdrawals, during retirement, while taking into account current and future pensions with and without cost-of-living adjustments.
On-going discussion and support is in this Bogleheads® forum topic: Variable Percentage Withdrawal.
Wiki link: Retiree Portfolio Model
The Retiree Portfolio Model is a downloadable Excel spreadsheet created by a retiree for retirees. It models the most common financial aspects of a retiree and their spouse’s lives, including pensions, Social Security benefits, living expenses, IRA Required Minimum Distributions, purchase of an annuity, sale of a house, and many other items including Federal and state income taxes. All of this data is used to create a model of their accounts over a period of 1 to 40 years.
A feature of this model allows the user to compare their normal portfolio results with one that includes alternative choices, such as doing Roth IRA conversions, choosing alternative Social Security starting ages and benefits, or buying a Single Premium Immediate Annuity. This model was created using Excel 2003 and is compatible with LibreOffice Calc and possibly Google Sheets. All formulas and results are completely viewable and can be unprotected, allowing user customization.
The model was developed by forum member BigFoot48.
The first post in this Bogleheads® forum topic: Retiree Portfolio Model contains the link for downloading the spreadsheet. Also use this topic to receive assistance or ask questions.
Some investors like to calculate their personal returns. This page provides a spreadsheet for Bogleheads to calculate their personal returns in a uniform manner.
The spreadsheet calculates two types of personal returns: an investor return which reports on how well the invested money has been growing so far, and a portfolio return which can be used to compare the past performance of the portfolio over a specific time period to widely available index and mutual fund returns or to the performance of another portfolio.
The spreadsheet also provides a growth of $10,000 chart for the portfolio.
On-going discussion and support for the spreadsheet is in this Bogleheads® forum topic: A Returns Spreadsheet for Bogleheads
Site link: The International Boglebot
Welcome to the unofficial Boglebot service!
Your Boglebot financial advisor will help collect your thoughts on asset allocations and provide some options as to what you could consider for your retirement portfolio.
Privacy policy: This website (boglebot.com) does not store any of your data. There are no cookies, no advertisements, no logs. All the choices you make stay in your browser and disappear when you close it.
Disclaimer: No guarantees are made as to the accuracy of the information on this site or the appropriateness of any advice to your particular situation.
Forum discussion topic: Volunteers to help with a Boglebot idea.
cFIREsim stands for Crowdsourced Financial Independence and Retire Early Simulator.
- The link to cFIREsim.
- The link to the forum discussion topic: Cfiresim has been revised and is super easy to use. (It’s based on Firecalc).
How do I know if my portfolio will last? At it’s most basic level, cFIREsim uses historical stock/bond/gold/inflation data from 1871 to present, and calculates how your portfolio would have fared throughout history. If you enter a 30 year simulation period, it will run your data for every 30yr period in history. Example: cFIREsim will figure out your portfolio value, if you would have theoretically retired for the period of 1871-1900, then for the period of 1872-1901, 1873-1902, etc. It will take all of your inputs and determine whether or not the portfolio “failed” (failure is defined as going below $0 at any given point). What does this tell me? If cFIREsim says that your portfolio survived 95% of the simulation cycles, it means that if the market does no worse than the worst years in recorded stock market history, your portfolio will survive.
What can cFIREsim do? At it’s core, you can enter information in a few simple inputs and return the basic simulation. At it’s most complicated, it can determine your portfolio success based on 80 individual portfolio adjustments, multiple types of inflation, multiple types of market returns, and graphically show you the results. There are many options to choose from outside of the “Basic Inputs”. You can find information for each section within this FAQ.
- Link to TIPs Ladder Builder: Link
- Link to forum discussion: New tool for building a TIPS ladder
The first page is a form to specify your desired annual real income and the contiguous years for which you want to receive that amount. Submitting the form produces a TIPS shopping list.
There is a button to expand the tabular shopping list to provide more details about the bonds to be bought, cost breakdown per rung, and income breakdown per rung. You can also download all the details into a CSV file which can be read into a spreadsheet for further analysis.
This tool cannot yet make a “lumpy ladder”, one in which the income requirement varies from year to year. It also cannot yet integrate existing TIPS holdings into a new ladder.

- Link to site: bogle.tools
- Forum post discussing the tool: bogle.tools/portfolio – tool to help collect and format Portfolio Review info
Site description
This site aims to provide useful tools to Bogleheads.org users.
It provides tools to help you:
Annual Saving – A tool to help apply bogleheads.org’s Prioritizing Investing to ensure you get the most for your savings $
Portfolio Review – A tool to help collect and format info about you and your portfolio (as per “Asking Portfolio Questions” from bogleheads.org)
Bogleheads.org Search – Use the search engine of your choice to focus on just the forums, wiki, etc…
3fund Performance – See daily / monthly / yearly / all-time performance of your three fund portfolio
Privacy – None of the answers you fill out on this site get sent to a server. All calculations are done on your device (PC/Phone/Tablet).
Programmers – This site is open source. See github.com/bogle-tools/site ↗️ for code and an issues list.