Financial tools
Run the numbers.
Then run your life.
Calculators, checklists and time machines for smarter money management, built on real market history wherever history exists. Every tool shows its assumptions, because a number you don't understand is just a guess.
01 · Flagship
Find your Singularity
The year your money starts earning more than you put in, and the year a 4% withdrawal could cover your spending. Learn the idea in lesson one.
Your Singularity
Year —
The year your money earns more than you add.
Escape velocity
Year —
When 4% a year covers your spending.
- Contributed
- —
- Growth earned
- —
- Balance
- —
Hypothetical illustration in today's dollars: contributions monthly, returns compounded monthly at a constant real rate. Real markets rise and fall, and returns are never guaranteed. Not investment advice.
02 · Real history
The DCA time machine
What if you had invested the same amount every month, no matter what the market did? Pick an asset and a start date and replay history, month by month, against putting it all in on day one.
Month-end prices. Index levels exclude dividends, so real-world index fund results would have been higher. Bitcoin prices from Coinbase. Past performance does not predict future results. Not investment advice.
03 · Since 1913
The inflation time machine
Inflation is the quiet tax on cash. See what a dollar was worth in any year since 1913, using the U.S. Consumer Price Index.
Annual averages of CPI-U (all urban consumers, not seasonally adjusted) from the U.S. Bureau of Labor Statistics via FRED; the latest year uses the latest month published.
04 · Mental math
The Rule of 72
Divide 72 by a yearly growth rate and you get, roughly, the years it takes money to double. It works for inflation and debt too, just in the wrong direction.
05 · Hidden costs
Fee drag
A 1% fee sounds small. Over decades it compounds against you, just as returns compound for you. Compare two yearly fees on the same plan.
Fees are charged monthly as a share of the balance. Hypothetical, constant returns; real returns vary. Learn more in Index funds and ETFs.