Guides / Rule of 72: How Long Does It Take to Double Your Money?
Rule of 72: How Long Does It Take to Double Your Money?
3 Oct 2026The rule of 72 says: divide 72 by the yearly return to estimate the years needed to double your money.
Rule of 72 vs exact
| Yearly return | Rule of 72 | Exact | To grow 10 times |
|---|---|---|---|
| 6% | 12.0 years | 11.9 years | 39.5 years |
| 8% | 9.0 years | 9.0 years | 29.9 years |
| 10% | 7.2 years | 7.3 years | 24.2 years |
| 12% | 6.0 years | 6.1 years | 20.3 years |
| 15% | 4.8 years | 5.0 years | 16.5 years |
The shortcut is very close for common rates. Try any rate in the Money Doubling Calculator.
Ways to use it
- Savings: at 4%, your money doubles in about 18 years.
- Inflation: at 6% inflation, prices double in about 12 years, so your money loses half its buying power. See how inflation works.
- Debt: at 42% on a credit card, a balance can double in under two years.
Remember
The rule shows rupees, not buying power. It also assumes a steady return, which markets do not give. For exact planning, use the Compound Interest Calculator.
Try the Money Doubling Calculator