Terms of Use for Longrun
Longrun: Retirement Test Published by OFO Labs
Last Updated: September 2026
Please read these Terms of Use carefully before using Longrun. By downloading or using the app, you agree to these terms.
Acceptance of Terms
By accessing or using Longrun, developed and published by OFO Labs, you agree to be bound by these Terms of Use. If you do not agree, do not use the app.
The App
Longrun tests a retirement plan against real market history. You enter a portfolio, a yearly spending figure, a length and an investment mix, and the app runs that plan against every month you could have retired since 1871, using the returns and the inflation that actually followed each of those months. All of the arithmetic happens on your device and the app makes no network requests.
Longrun is not financial advice
This is the most important thing in these terms, so it is not buried.
Longrun is a calculator. It is not financial, investment, tax, pension or retirement advice, and it must not be used as a substitute for advice from someone qualified to give it.
- It does not know your tax position, your health, your family, your other assets, your debts, your country's pension rules, or anything else about your circumstances.
- It does not recommend, rate or endorse any security, fund, product or provider, and it never will.
- It is not connected to any bank, broker or pension provider, holds no money, and cannot make any transaction.
- OFO Labs is not a financial adviser, a broker, or a regulated financial firm in any jurisdiction, and nothing in the app should be read as a personal recommendation.
Past performance is not a guide to future results. A plan that survived every historical retirement in the app's data set can still fail in the future, because the future is not obliged to resemble the past. Do not treat any figure the app produces as a prediction, a guarantee, or a safe amount to spend.
Decisions about your retirement are yours, and you make them at your own risk. Please talk to a qualified professional before acting.
What we promise about the numbers
We think this belongs in the terms rather than only in the marketing.
The market data bundled with Longrun is Robert J. Shiller's monthly United States series: the S&P Composite price and dividends, consumer prices, and the long term interest rate, published by Yale University for free use. Longrun uses it to build monthly total returns for stocks, a monthly total return for a rolling ten year Treasury, and monthly inflation. The bond series is modelled from the yield rather than observed, because no monthly bond total return index reaches back to 1871, and the app says so.
The withdrawal strategies are published ones and are named after their authors: constant dollar from Bengen 1994, the decision rules from Guyton and Klinger 2006, variable percentage withdrawal from the Bogleheads community, and floor and ceiling. Guyton and Klinger's fourth rule, about which asset to sell from, changes no withdrawal amount and is not modelled.
Our test suite checks the bundled series against published long run figures and checks the simulator against published results, including the well known outcome for a 4% withdrawal over thirty years. If you find a figure you believe is wrong, please tell us. Correctness is the entire product.
Longrun Pro
The full historical test on the constant dollar strategy, the complete chart, the success rate, the failing years and the year by year detail of any of them are available to everyone, permanently and in full, with one saved plan.
Longrun Pro is a one-time purchase, not a subscription. It adds the other four withdrawal strategies, pensions and other income, glide paths, the safe withdrawal rate finder, resampled futures, unlimited saved plans and CSV export.
Purchases are processed by Apple and are subject to Apple's terms. Refunds are handled by Apple, not by us. If you delete and reinstall the app, or install it on another device using the same Apple Account, use Restore to recover your purchase.
Your content
Your plans are stored on your device and belong to you. We never receive them and cannot recover them for you if you delete the app.
Acceptable use
Do not decompile, reverse engineer or redistribute the app, and do not present its output as professional advice to anyone else.
Disclaimer of warranties
The app is provided "as is", without warranty of any kind, express or implied, including fitness for a particular purpose. We do not warrant that it is free of errors.
Limitation of liability
To the fullest extent permitted by law, OFO Labs is not liable for any loss, financial or otherwise, arising from your use of the app or from any decision you make on the basis of anything it shows you.
Changes
We may update these terms. Material changes will be published here with a new date.
Contact
ofolabs@gmail.com