How Long to Double Money at 13%
At 13% a year, money doubles in 5.7 years. The Rule of 72 says 5.5.
Doubles in
5.7 years
Quadruples in
11.3 years
Grows 8 times in
17.0 years
Rule of 72 estimate
5.5 years
What different amounts become
| Start | After 5.7 years | After 11.3 years | After 17.0 years |
|---|---|---|---|
| $1,000 | $2,000 | $4,000 | $8,000 |
| $5,000 | $10,000 | $20,000 | $40,000 |
| $10,000 | $20,000 | $40,000 | $80,000 |
| $25,000 | $50,000 | $100,000 | $200,000 |
| $50,000 | $100,000 | $200,000 | $400,000 |
| $100,000 | $200,000 | $400,000 | $800,000 |
Growth over time at 13%
| Years | $1,000 becomes | $10,000 becomes | Growth |
|---|---|---|---|
| 5 | $1,842 | $18,424 | 1.84x |
| 10 | $3,395 | $33,946 | 3.39x |
| 15 | $6,254 | $62,543 | 6.25x |
| 20 | $11,523 | $115,231 | 11.52x |
| 25 | $21,231 | $212,305 | 21.23x |
| 30 | $39,116 | $391,159 | 39.12x |
| 40 | $132,782 | $1,327,816 | 132.78x |
| 50 | $450,736 | $4,507,359 | 450.74x |
How it is worked out
Years to double = ln(2) / ln(1 + r)
ln = natural logarithm, r = rate as a decimal.
The Rule of 72 is the shortcut version. Divide 72 by the rate.
At 13% the shortcut is off by 0.1 years.