Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Financial
Simple Interest Calculator
Compute interest on a principal amount using the simple interest formula I = P × r × t. Useful for short-term loans, government bonds, and settlement estimates.
Fill in the required fields to see your result.
Economics
Compound Interest Calculator
Project the future value of a lump-sum investment when interest is reinvested each year using A = P · (1 + r)ᵗ. The simplest compounding model — assumes annual compounding, a constant rate, and no additional contributions or withdrawals.
Fill in the required fields to see your result.
Key differences
| Simple Interest Calculator | Compound Interest Calculator | |
|---|---|---|
| Category | Financial | Economics |
| Inputs required | 3 | 3 |
| Result | Interest Earned (USD) | Final Amount ($) |
| What it does | Compute interest on a principal amount using the simple interest formula I = P × r × t. Useful for short-term loans, government bonds, and settlement estimates. | Project the future value of a lump-sum investment when interest is reinvested each year using A = P · (1 + r)ᵗ. The simplest compounding model — assumes annual compounding, a constant rate, and no additional contributions or withdrawals. |