Check your retirement and your investments against real market history.
Free calculators that open on a worked example and show every assumption. Change the numbers to make it yours: no sign-in, and we keep nothing you enter.
Will my money last?
A retirement plan in today's dollars: whether it lasts, what would make it last, and how it held up over market history.
Worked example: a 40-year-old with the median savings →
Am I invested well?
What your funds and your adviser cost you, in dollars, this year and over 20 years.
Worked example: $500,000 with a 1% advisory fee →
What would this mix have done?
Any mix of funds on decades of total-return data: the growth, the worst declines and how long they lasted.
Worked example: a classic 60/40 against the reference mix →
How it works
- Start from an example. Each calculator opens on a worked example, already run. Change any number and run it again.
- We keep nothing you enter. It stays in the page's address, and your browser remembers each calculator's last numbers until you clear them. You can share the link, with or without your amounts.
- Every number comes from code. Calculations on market data and your inputs, with each assumption stated on the page. No AI estimates a figure.
Why trust these numbers
The calculators run on the data and code of our research lab, which publishes how every number is made, including what didn't work.
- Methodology: how the numbers are made, and the definitions behind every metric.
- The ledger of nulls: why we publish the tests that failed.
- Model portfolios: pre-registered before they ran, with their full record.
- The data: every fund's history, and where and how it was extended before a fund existed.
Hypothetical performance: every model figure is a historical simulation, not a prediction, not advice.
Kaight, an AI planner that runs these same calculations on your own facts and explains them, is in private beta.