The way a TVM calculator works is “money out of your pocket is negative (investment) and money into your pocket is positive (bank loan)”. This only applies to PV and PMT. If you invest $1 (PV) out of your pocket (-) and it goes to $10 (FV) in 10 years (PERIODS and ANNUAL) then the Compound Annual Growth Rate (CAGR) is 25.9%.
If you invest a $1 and it doubles in 3 years the CAGR is 26%. This mean an investment that doubles every three year will 10x over 10 years. Here is that schedule.
| Year | $ |
|---|---|
| 2026 | 1 |
| 2029 | 2 |
| 2032 | 4 |
| 2035 | 8 |
| 2036 | 10 |
| 2038 | 16 |
| 2041 | 32 |
| 2044 | 64 |
| 2046 | 100 |
| 2047 | 128 |
Notice that when you put the slider at 2x, the CAGR of 7.2% is the same as the Rule of 72 divided by 10 years equals 7.2%. While I was working, I only invested in the S&P 500 trying to get my 401k to grow at 10%, or double every 7.2 years. Hopefully, even a 3x in 10 years (11.6%). Of course now that won't even keep up with inflation.