Loan Calculator
Estimate monthly payments and total interest on a loan.
This tool runs entirely in your browser. Your files are never uploaded to a server.
Uses the standard fixed-rate installment formula with one constant rate for the whole term; it does not include fees, insurance, or a lender's specific rounding.
386.66
Monthly payment
3199.36
Total interest
23199.36
Total paid
What this calculator does
Estimates the fixed monthly payment for a standard installment loan, along with the total interest and total amount paid over the full term.
How to use it
Enter the loan amount, a nominal annual interest rate, and the term in years. Use one currency consistently and a rate that matches how the loan actually compounds.
Worked example
A 20,000 loan at 6% annual interest over 5 years (60 months) has an estimated monthly payment of about 386.66, total interest of about 3,199.36, and a total amount paid of about 23,199.36. Automated tests verify this figure.
Formula
For principal P, monthly rate r and n monthly payments, payment = P × r ÷ [1 − (1 + r)⁻ⁿ]. At a 0% rate, the payment is simply the loan amount divided evenly across the number of months, since there is no interest term to spread.
Assumptions and limits
The model assumes one constant nominal annual rate, monthly compounding, and a payment made on schedule every month for the entire term. It does not model variable rates, extra or missed payments, or a lender's specific rounding rules — the Amortization Schedule calculator covers a month-by-month breakdown with optional extra payments.
What is excluded
Results reflect principal and interest only. Origination fees, insurance, taxes, and other charges a specific loan product may include are not part of this estimate — compare against your lender's official quote before making a decision.
Scope, sources and privacy
This is an educational estimate, not a loan offer or financial advice. The payment formula follows standard installment-loan amortization as described in Consumer Financial Protection Bureau lending guidance. Reviewed September 2026. Calculation runs locally in the browser; Quiklio does not upload the entered values.
Frequently Asked Questions
- How is the monthly payment calculated?
- It uses the standard amortization formula for a fixed-rate installment loan, P × r ÷ [1 − (1 + r)⁻ⁿ], which spreads principal and interest across the term so every payment is the same amount.
- Does it account for fees or insurance?
- No — it estimates payments based purely on principal, rate and term. Origination fees, insurance premiums and other charges a real loan might include are not part of this estimate.
- How is this different from the Amortization Schedule calculator?
- This tool gives you the headline numbers — payment, total interest, total paid — while the Amortization Schedule calculator breaks the same loan into a month-by-month table and lets you model extra principal payments.