Debt payoff estimator
Compare repayment time with extra payments and identify balances that cannot be paid off in this model. Change the inputs to update the chart or diagram.
Your inputs
The editable example is illustrative. Enter your own dimensions, operating data, prices, and fees. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
How it works
- B′ = × (1 + ÷ 1,200) + − ; ≤ Ending balance + Modeled interest +
- Worked example: 1,000 ÷ 100 = 10 months (r=0); 1,000 × 0.01 = 10 Modeled interest ⇒ 10 = Modeled interest 10 ⇒ ΔB = 0
- Supported input limits: : 0 ≤ x ≤ 1,000,000,000,000; : 0 ≤ x ≤ 1,000; : 0 ≤ x ≤ 1,000,000,000,000; : 0 ≤ x ≤ 1,000,000,000,000; : 0 ≤ x ≤ 1,000,000,000,000
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
Interest and the entered fee are added monthly before payment. The comparison adds your extra payment every month. An unresolved result means the debt does not shrink sufficiently or remains after 1,200 months; it does not mean the debt is cleared.
Sources
- CFPB — amortization and principal/interest Sources reviewed: 2026-10-06
