Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Personal Finance
Debt Payoff Calculator
Calculate how many months it takes to pay off a single debt at a fixed APR — either by making only the minimum payment or by paying a chosen monthly amount. Use it to compare the long-term cost of paying minimums versus accelerating payoff.
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
| Debt Payoff Calculator | Compound Interest Calculator | |
|---|---|---|
| Category | Personal Finance | Economics |
| Inputs required | 4 | 3 |
| Result | Months to Pay Off (months) | Final Amount ($) |
| What it does | Calculate how many months it takes to pay off a single debt at a fixed APR — either by making only the minimum payment or by paying a chosen monthly amount. Use it to compare the long-term cost of paying minimums versus accelerating payoff. | 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. |