Mortgage Amortization & Refinance Calculator

See your real remaining balance curve, exactly what an extra monthly payment saves, and whether refinancing actually pays for its own closing costs.

Reading This Tool

How To Use This Calculator

Enter your original mortgage details and how many years you've already paid, then test an extra payment or a new rate.

The chart tracks your remaining balance with and without the extra monthly payment, the gap between the two lines is real money and real time. The refinance break-even shows how many months it takes for the lower payment to pay back the closing costs, before comparing that to how much loan term you actually have left.

Your Inputs

Original Loan Amount $450,000

Original Interest Rate 5.25%

Original Amortization

Years Already Paid 3 yrs

Extra Monthly Prepayment $200

New Refinance Rate 4.50%

Refinance Closing Costs $3,000

The refinance scenario keeps your remaining amortization the same length at the new rate. Years Already Paid is automatically capped below your amortization length.

Where You Stand Today

Current Monthly Payment

Interest Saved By Prepaying

Time Saved By Prepaying

0 yrs

New Payment After Refinance

Monthly Savings, Refinancing

Refinance Break-Even

Remaining Balance, With & Without Extra Payments

Original Schedule With Extra Payment

Assumes a fixed rate, monthly compounding and no prepayment penalties, real mortgages (especially fixed-term ones) often charge an interest rate differential or three-months-interest penalty to break early. Confirm your actual penalty before refinancing.

Refinancing, or buying an investment property?

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