How Loan Payments Are Calculated
Monthly loan payments use the amortization formula: M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the principal, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. Each payment covers interest first, then reduces the principal balance.
Loan Type Comparison
| Loan Type | Typical Rate (2025) | Common Term |
|---|---|---|
| Auto Loan (new) | 5–8% | 48–72 months |
| Auto Loan (used) | 7–12% | 36–60 months |
| Personal Loan | 8–20% | 24–84 months |
| Student Loan (federal) | 5–8% | 10–25 years |
| Mortgage (30-yr fixed) | 6–7.5% | 30 years |