Loan repayment
Estimate monthly payments, interest and payoff time, including optional extra payments. Drag the graph handles to change inputs and explore the result.
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
- r = ÷ 1,200; Monthly principal and interest = × r ÷ (1 − (1+r)^−); r=0: ÷ ; Payment ≤ Ending balance + Modeled interest
- Worked example: 1,200 ÷ 12 = 100 (r=0); 10,000 × 0.01 ÷ (1 − 1.01^−12) ≈ 888.4878868
- Supported input limits: : 0 ≤ x ≤ 1,000,000,000,000; : 0 ≤ x ≤ 1,000; : 1 ≤ x ≤ 1,200; : 0 ≤ x ≤ 1,000,000,000,000
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
The model uses a fixed annual rate divided by 12 and monthly payments. Extra payments shorten repayment while the displayed base payment stays unchanged. It excludes lender fees and daily interest; the schedule stops after 1,200 months.
Sources
- CFPB — amortization and principal/interest Sources reviewed: 2026-10-06
