If you invest a lump sum once and make no further deposits, a $10,000 investment at 7% becomes $20,097 after 10 years, $40,387 after 20 and $81,165 after 30. Each additional decade multiplies the balance by about two.
Growth of a single deposit at 7%
| Starting amount | After 10 years | After 20 years | After 30 years |
|---|---|---|---|
| $5,000 | $10,048 | $20,194 | $40,582 |
| $10,000 | $20,097 | $40,387 | $81,165 |
| $25,000 | $50,242 | $100,968 | $202,912 |
| $50,000 | $100,483 | $201,937 | $405,825 |
This is useful for windfalls such as a bonus or inheritance. Compare it with paying down debt: a card at 24% costs far more than a 7% return gains.
What we assumed
- Returns are an assumed constant annual rate compounded monthly. Real markets vary year to year.
- Deposits are made at the end of each month unless stated.
- Taxes, fees and inflation are ignored unless the table says otherwise.
- No deposits or withdrawals after the first.
Related calculators: Compound Interest Calculator, Credit Card Payoff Calculator.
Questions people ask
Should I invest it all at once?
Historically, investing sooner has beaten spreading it out more often than not, but that is no promise. Some people prefer to spread it to reduce regret.
Estimates for general education, not financial, tax or legal advice. Real results depend on your lender, employer, tax situation and location. See the disclaimer.