Refinance Calculator Formula & How It Works
- Old Payment = Current monthly P&I
- New Payment = New monthly P&I at new rate/term
- Closing Costs = typically 2–5% of loan amount
- Break-Even = months until total savings exceed closing costs
Refinancing makes sense when you stay in the home past the break-even point. If closing costs are $6,000 and you save $200/month, break-even is 30 months. If you plan to move in 2 years, refinancing loses money.