Free online mortgage refinance calculator

How to use

1. Enter your current remaining loan balance, interest rate, and the number of months left.
2. Enter the new interest rate you’ve been quoted and the new loan term in months.
3. Add all closing costs (origination, appraisal, title, etc.).
4. Click Calculate refinance to see monthly savings, break-even, and interest totals.

The formula

Monthly payment uses the standard amortization formula:

Payment = P × r × (1 + r)^n / ((1 + r)^n − 1)

Where P is the balance, r is the monthly rate (annual rate ÷ 12), and n is the number of months. Break-even months = closing costs ÷ monthly savings.

Worked example

Balance: $250,000. Current rate: 7% with 300 months left. New rate: 6.5% for 360 months. Closing costs: $4,000.

• Current payment ≈ $1,766/month
• New payment ≈ $1,580/month
• Monthly savings ≈ $186
• Break-even ≈ 22 months

If you plan to stay more than 22 months, refinancing saves money.

Notes

• A lower rate doesn’t always mean lower total cost — extending your term can increase total interest paid even if monthly payments fall.
• This calculator does not account for private mortgage insurance (PMI) changes, tax deductibility of interest, or opportunity cost of closing costs.
• Cash-out refinances involve borrowing more than the current balance; this calculator models rate-and-term refinances only.