Calculator Inputs
Enter your current mortgage details and proposed refinance terms. Results appear above this form after submission.
Formula Used
1) Monthly principal and interest
M = P × r × (1 + r)n ÷ ((1 + r)n − 1)
Where P is loan amount, r is monthly interest rate, and n is total monthly payments.
2) Refinance loan amount
New Loan Amount = Current Balance + Cash Out + Financed Closing Costs + Financed Points
3) Monthly savings
Monthly Savings = Current Full Monthly Payment − New Full Monthly Payment
Full payment includes principal, interest, tax, insurance, PMI, and HOA.
4) Break-even period
Break-even Months = Upfront Cash ÷ Monthly Savings
This works when monthly savings are positive. If savings are not positive, break-even is not reached.
5) Lifetime savings
Lifetime Savings = Current Remaining Cost − Refinance Remaining Cost
Remaining cost includes loan payments, escrow items, and any upfront refinance cash.
How to Use This Calculator
- Enter your current mortgage balance, rate, and remaining term.
- Add current tax, insurance, PMI, HOA, or your real monthly principal and interest.
- Enter proposed refinance rate, new term, closing costs, points, and any cash out amount.
- Choose whether closing costs or points are financed into the new loan.
- Add the new tax, insurance, PMI, and HOA amounts if they change.
- Include an extra monthly payment if you plan to pay the new loan faster.
- Click Calculate Refinance to view savings, interest changes, payoff timing, and break-even results.
- Use the CSV or PDF buttons to export the summary after calculation.
Example Data Table
| Current Balance | Current Rate | Remaining Term | New Rate | New Term | Closing Costs | Points | Cash Out | Extra Payment |
|---|---|---|---|---|---|---|---|---|
| $285,000 | 6.85% | 24 years | 5.90% | 20 years | $4,800 | 0.75% | $0 | $100 |
| $410,000 | 7.10% | 27 years | 6.20% | 30 years | $6,500 | 1.00% | $20,000 | $0 |
| $190,000 | 6.40% | 18 years | 5.45% | 15 years | $3,200 | 0.00% | $0 | $150 |
FAQs
1) What does a refinance mortgage calculator show?
It estimates your new payment, loan amount, interest cost, break-even period, payoff speed, and long-term savings. It helps compare your current mortgage with a proposed refinance using consistent inputs.
2) Why is break-even important?
Break-even shows how long monthly savings need to recover upfront refinance cash. If you may sell or move before that point, refinancing may not deliver the value you expect.
3) Should I finance closing costs?
Financing costs reduces upfront cash, but it increases your loan balance and interest paid over time. Paying costs upfront may improve long-term savings if you can comfortably afford it.
4) Do taxes and insurance matter in refinance decisions?
Yes. They do not change loan interest, but they affect your full monthly housing payment. Including them gives a more realistic comparison between current and new payment obligations.
5) What happens if I take cash out?
Cash out increases the new loan amount. That usually raises monthly payment and total interest, even if the new rate is lower. It can still help if you need liquidity.
6) Why might monthly savings look good but lifetime savings look worse?
A longer new term can lower the monthly payment while increasing total interest over time. That is why both short-term payment relief and long-term total cost should be reviewed together.
7) Does making extra payments change the result?
Yes. Extra payments can shorten payoff time and reduce total interest. However, they also increase your actual monthly cash outflow, so monthly savings may shrink or disappear.
8) Can this calculator replace a lender quote?
No. It is a planning tool. A lender quote may include precise fees, escrow rules, credit-based pricing, and underwriting conditions that change the final refinance numbers.