Lifetime Investment Calculator — Paul Merriman
55 Years of Data · Up to 200-Year Horizons

Lifetime Investment Calculator.

Simulate long-term portfolio growth using 55 years of historical market data — wars, booms, busts, and inflationary periods all included.

Updated: October 2025 Data: 1970–2024 Built by: Craig Appl
About this Tool

A dynamic, interactive lifetime simulator.

The Merriman Financial Education Foundation Lifetime Investment Calculator helps investors simulate long-term portfolio growth using historical market data. Built upon the "Fine Tuning Your Asset Allocation" 2026 update tables , it leverages 55 years of market history (1970–2024) — encompassing various economic cycles such as wars, booms, busts, and inflationary periods — to model potential investment outcomes over periods extending up to 200 years by looping through this historical sequence.

It's an educational tool — a hands-on way to explore how various investment strategies and asset allocations might perform over extended periods. The goal is to help you make informed choices aligned with your financial goals, not to predict the future.

Key Features

Six levers, endless scenarios.

01 / Strategy
Strategy Selection
Choose from 11 Merriman-endorsed strategies — S&P 500, Ultimate Buy & Hold, 4-Fund Combo, All-Value, and All-Small-Cap-Value — in U.S.-only or global flavors.
02 / Mix
Asset Allocation
Adjust equity-to-fixed-income ratios from conservative (0% stocks / 100% bonds) all the way up to aggressive (100% stocks / 0% bonds).
03 / Inflation
Nominal vs. Real
Toggle between future dollars (nominal) and today's dollars (real) to see the true impact of inflation on growth over decades.
04 / Scenario
Starting Year
Pick any year between 1970 and 2024 as your starting point — including right before major bear markets like 1973–74 or the early 2000s.
05 / Horizon
Investment Duration
Define your timeline anywhere from 1 to 200 years — long enough to model multiple generations of wealth.
06 / Amount
Initial Investment
Enter a starting lump sum and watch how different strategies and allocations affect the final portfolio value.
Launch the Calculator

Run your scenarios.

The dashboard loads below. On desktop it fills the full width; on smaller screens, use the built-in Tableau controls to zoom and scroll.

Tip: Use the download button inside the Tableau toolbar to export any sheet to Excel. The "Crosstab" option works best for exporting a view similar to the visualization.
Parameter Reference

Every setting, explained.

A full reference for every input on the dashboard — what it does and what values it accepts.

Name Description Options / Range
Strategy Choose from the 11 Merriman strategies you've been hearing about for years.
  • B1: S&P 500
  • B2a: Ultimate Buy & Hold WW (50/50)
  • B2b: Ultimate Buy & Hold WW (70/30)
  • B3a: 4-Fund Combo WW (50/50)
  • B3b: 4-Fund Combo WW (70/30)
  • B4: 4-Fund Combo US only
  • B5a: All Value WW (50/50)
  • B5b: All Value WW (70/30)
  • B6: All Value US
  • B7a: All Small Cap Value WW (50/50)
  • B7b: All Small Cap Value WW (70/30)
  • B8: All Small Cap Value US
  • B9: US 2-Fund (50% S&P 500 / 50% SCV)
Equity / Fixed Income Toggles the columns from 0% stock / 100% bond to 100% stock / 0% bond. 0% – 100% equity
Nominal or Real Display values in future (nominal) or today's (real) dollars. Nominal · Real
First Sequence Year The first year in your sequence of returns — e.g., simulate a portfolio that started right before the 1973–74 or early-2000s bear markets. 1970 – 2024
Duration Total number of years to display. 1 – 200 years
Starting Value A lump sum to start with. Minimum $0
Change Historical Returns By Adjusts the historical return by the input value. For example, if the historical return was −5% in a given year and you enter −1%, the calculated return becomes −6%. −100% to +100%
First Contribution Year The first year contributions begin. 1 – 200
Contribution Duration Duration of contributions. 0 – 200 years
Contribution Amount (Nominal) Nominal amount contributed at the beginning of each year. Minimum $0
Scale Cont./Dist. w/ Inflation Scales contributions and distributions with inflation so you contribute or distribute the same real value each year. Yes · No
Distribution Toggles the table between showing growth columns ($ Return & % Return) vs. showing fixed or flexible distributions.
  • Don't Calculate
  • Fixed:% Start Val
  • Flexible:% Portfolio Val
First Distribution Year The first year you start taking a distribution. Ignored if Distribution = "Don't Calculate." 1 – 200
Distribution Duration The number of years you take a distribution. Ignored if Distribution = "Don't Calculate." 1 – 200 years
Distribution % Percent to take for your fixed or flexible distribution. Fixed uses the percentage in the first distribution year; Flexible recalculates each year. Fixed can be scaled with inflation via the Scale parameter. Ignored if Distribution = "Don't Calculate." Minimum 0%
Frequently Asked

Questions we hear often.

Where does the underlying data come from?

The dashboard is built from the 2025 Fine Tuning tables (1970–2024). We have 55 years of data, which we loop through so you can evaluate up to 200 years of returns.

Why does the calculator loop back to 1970 after 2024?

We only have 55 years of data from 1970 to 2024. Looping through the sequence lets you see how returns could play out across multiple generations. Pick any starting year — after 2024, the sequence loops back to 1970.

What assumptions were made?

All contributions are added at the beginning of the year.

All distributions are taken at the beginning of the year.

Where do the inflation calculations come from?

Inflation is based on the historical U.S. Consumer Price Index for each sequence year.

How can I download the table to Excel?

Each sheet can be downloaded to Excel using the download button in the Tableau toolbar. The "Crosstab" option works best for exporting a view similar to the on-screen visualization.

I found an issue — what should I do?

Please email craig@paulmerriman.com for any technical issues.

Which technology is used?

The Merriman Online Calculator is built using Tableau Public.

How can I embed the dashboard on my own website?

We appreciate your interest! Please link to this page where possible — it will always have the most current version.

Why did you choose a maximum of 200 years?

It felt like one could model multiple lifetimes across a 200-year horizon. The choice was inspired by Benjamin Franklin's 200-year bequest to the cities of Boston and Philadelphia.

How are expenses handled?

The Fine Tuning tables include adjustments for expenses. We used real expenses where data was available and estimated expenses where it wasn't.

Why are some lines in the table red?

Red text means the previous year's end-of-year balance was greater than the current year's end-of-year balance — i.e., the portfolio shrank that year.

Can you change the "Year" column to show the actual calendar year?

We discussed this extensively during the build. We purposefully chose not to show future calendar years because this tool isn't able to predict anything. Once the sequence exhausts our data, it loops back to 1970 — which is harder to interpret if labeled with future dates.

Why is the distribution $ amount constant every year when I choose "Real" instead of "Nominal"?

Contributions and distributions stay flat in real terms when "Scale Contr./WDL w/ Inflation" is set to Yes and "Nominal or Real" is set to Real. Without scaling, they decline in real terms because purchasing power decreases each year. If you keep up with inflation, purchasing power stays constant.

How does the "Change Historical Returns By" field work?

The field takes a value between −100% and +100% and adds that value to the return for all years. Enter −10% and every year's return is reduced by 10 percentage points — so a −5% year becomes −15%.

How do contributions work when "Real" is selected?

The Contribution Amount (Nominal) parameter is always entered in nominal dollars. The table then adjusts the contribution amount in real terms relative to the first year of the table.

For example: if you start the evaluation in year 1 and contributions begin in year 10, the first contribution appears in year-1 dollars, adjusted for inflation — mirroring the behavior when you choose Nominal (where the year-10 contribution is in year-10 dollars and inflates from there).

Change Log

Updates and revisions.

2025-10-28
  • Launched the 2025 calculator update based on the 2025 Fine Tuning tables. Table numbers are the same as last year.
  • Updated default values to reflect a 55-year duration and a 35-year distribution duration.
2024-05-28
  • Launched the 2024 calculator update based on the 2024 Fine Tuning tables. Table numbers are different this year.
  • Updated default values to reflect a 54-year duration and a 34-year distribution duration.
2022-02-16
  • Added the 2022 Fine Tuning tables. Table numbers are different this year and we added two new tables.
  • Updated default values to reflect a 52-year duration and a 32-year distribution duration.
2021-09-01
  • Fixed the 1970 CPI and real return — the original was understating inflation in 1970 by about 5%.
  • Significantly improved inflation calculations in real terms.
  • Contributions and distributions remain flat when Nominal/Real = "Real" and Scale = "Yes" because purchasing power stays constant.
  • Contributions and distributions decrease when Nominal/Real = "Real" and Scale = "No" because purchasing power decreases.
  • Fixed a calculation presenting real contributions and distributions that overstated growth in real terms.
  • Found and fixed rounding errors in the CPI calculation — these had an impact on real-term figures.
  • Rounded underlying calculations to the nearest cent instead of the nearest dollar.
  • Fixed distributions now end at $0 when you run out of money.
  • Added bold vertical lines between equity and fixed income allocations for improved visibility.
Questions? Issues?

Reach out to Craig.

For technical issues or feedback on the calculator, email Craig Appl — the developer behind this tool.

craig@paulmerriman.com →