What happens to $50,000 at 5% over 15 years?
If you invest $50,000 today at a 5% annual interest rate and leave it untouched for 15 years — with interest compounding annually — you end up with $103,946.41. That means your original principal earns $53,946.41 in compound interest, bringing your total return to 107.9% over the investment period.
The key driver is compounding: each year you earn interest not only on your original $50,000, but also on all the interest that has accumulated in prior years. In year one you earn $2,500.00, but by year 15 that annual interest payment grows to $4,949.83 — the same percentage applied to a much larger base.
At 5%, money doubles approximately every 14.2 years (Rule of 72: 72 ÷ 5 = 14.4). Over a 15-year horizon that translates to a 2.08x growth multiple.
These figures assume a constant 5% rate, annual compounding, and no withdrawals or additional deposits. Use the interactive calculator below to model monthly contributions, different compounding frequencies, or any custom scenario.