| Principal Amount | |
| Total Interest | |
| Total Amount |
| Year | Principal | Interest | Total |
|---|
| Starting Principal | |
| Total Contributions | |
| Total Interest Earned | |
| Total Amount |
| Year | Principal | Contributions | Interest | Total |
|---|
This calculator computes both simple interest (calculated only on the original principal) and compound interest (calculated on principal plus previously earned interest) — showing how much more compound interest earns over time, especially with more frequent compounding and additional regular contributions.
Example: $10,000 at 5% for 5 years earns a fixed amount under simple interest, but noticeably more under compound interest — the gap widens further with monthly or daily compounding.
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus any previously earned interest — meaning your interest earns interest over time.
A = P × (1 + r/n)^(nt) where A = final amount, P = principal, r = annual interest rate, n = compounding frequency per year, and t = time in years.
Interest can compound annually, semi-annually, quarterly, monthly, weekly, or daily. The more frequently it compounds, the higher the final amount for the same stated rate.
Starting early is the most powerful factor in compound interest growth. Reinvesting your interest rather than withdrawing it allows the compounding effect to fully work in your favor.
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus any previously earned interest, meaning your interest earns interest over time.
A = P x (1 + r/n)^(nt), where A is the final amount, P is the principal, r is the annual interest rate, n is the compounding frequency per year, and t is time in years.
Interest can compound annually, semi-annually, quarterly, monthly, weekly, or daily. The more frequently it compounds, the higher the final amount for the same stated rate.
Yes, it computes both simple and compound interest on any investment or loan based on your principal, annual interest rate, and time period.
Starting early is the most powerful factor in compound interest growth. Reinvesting your interest rather than withdrawing it allows the compounding effect to fully work in your favor.