Tool: Mortgage refinance calculator · Embed · All how-we-calculate pages · Questions
Purpose
Compare a current amortizing balance (rate and months remaining) with a new fixed-rate loan (new rate, term, optional cash-out and closing costs). Educational only.
Current path
Standard fixed-rate amortization on the remaining balance for the months left, using the current rate sample you type.
New path
- Starting principal = remaining balance + optional cash-out
- If you roll closing costs in, they are added to principal
- Amortize at the new rate for the new term in months
Savings and break-even
- Monthly savings = current payment − new payment
- Interest savings = current total interest − new total interest (full remaining paths)
- Cash break-even months = cash closing costs ÷ monthly savings (only when costs are not rolled in and monthly savings > 0)
What we intentionally leave out
- Live rates, credit scores, and lender fees beyond your cost input
- Points, buydowns, PMI changes, and escrow differences
- Taxes on cash-out and opportunity cost of cash closing costs
- Prepayment penalties and recast options
Related
Last reviewed: August 9, 2026.
YMYL notice: This site is for education only. It is not financial, tax, or investment advice. Nestfigure is not a bank, credit union, broker, investment adviser, or fiduciary. Product terms, rates, and penalties vary—always read your institution’s disclosures before acting. Calculator results are mathematical estimates, not bank quotes.