Refinance Payment Calculator
RefinanceUSA is not a lender. Results are estimates — actual payments vary by lender and loan type. How we calculate
How Refinancing Changes Your Monthly Payment
Your new monthly P&I payment is determined by three variables: the loan balance, the interest rate, and the loan term. Changing any one of them changes your payment.
Rate Drop — Same Term
The most common refinance scenario: same balance and term, lower rate. A 1% rate reduction on a $350,000 30-year loan saves roughly $220/month.
Example: $350,000, 30-year loan
| At 7.50% | $2,447/mo |
| At 7.00% | $2,329/mo |
| At 6.50% | $2,212/mo |
| At 6.00% | $2,098/mo |
| Saving (7.5% → 6.0%) | $349/mo |
Term Shortening — 30-Year to 15-Year
Refinancing to a shorter term almost always raises your monthly payment, even when the rate is lower — you're paying the same balance in half the time. The trade-off is dramatically less total interest.
Example: $280,000 balance
| 30 years at 6.75% | $1,815/mo → total interest $373,400 |
| 15 years at 6.10% | $2,384/mo → total interest $149,100 |
| Monthly payment increase | +$569/mo |
| Total interest savings | $224,300 |
When Refinancing Increases Your Payment
If you're far into your current loan (e.g., 15 years into a 30-year) and you refinance into a new 30-year, you're resetting the clock. Even at a lower rate, your payment might drop slightly — but you'll pay far more total interest. Use the milestones table in this calculator to see exactly where you'd stand after 5 and 10 years.
Understanding the Amortization Milestones
The milestone table shows your remaining balance and cumulative interest paid at 5-year intervals. This tells you two important things:
- Equity build-up: How quickly are you paying down principal vs. interest? In the early years of a 30-year mortgage, over 80% of each payment goes to interest.
- Cost of selling early: If you sell or refinance again before year 5 or 10, your balance hasn't dropped much from origination. Most of what you've paid has been interest.
Related Calculators
- Refinance Break-Even Calculator — How many months until monthly savings recover your closing costs?
- Mortgage Savings Calculator — Total interest saved over the full loan life vs. your current loan
- Main Refinance Calculator — Compare multiple lender offers side by side with closing costs and net savings
- HELOC vs Refinance Calculator — Which is cheaper for tapping equity: a HELOC or a cash-out refi?
- No-Closing-Cost Calculator — Pay upfront, roll in, or lender credit — which costs least?
Estimate Your New Payment
- How to Estimate Your New Mortgage Payment — The P&I formula explained with worked examples
- Refinance to a 15-Year Mortgage: Is It Worth It? — Payment comparison and interest savings analysis
- How to Compare Refinance Offers Side by Side — APR, total cost, and break-even comparison guide
Frequently Asked Questions
How do I calculate my new mortgage payment after refinancing?
Use the standard amortization formula M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where P is your loan balance, r is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the total months (years × 12). This calculator applies that formula automatically.
How much does a 1% rate decrease save per month?
On a $300,000 30-year loan, dropping from 7% to 6% saves about $190/month. On a $400,000 loan the same rate drop saves about $253/month. The exact savings depend on your balance, term, and how much principal you've already paid down.
Does refinancing to a shorter term lower my payment?
Usually no. Refinancing from a 30-year to a 15-year loan typically raises your monthly payment because you're amortizing the same balance over fewer months — even at a lower rate. The benefit is dramatically lower total interest. Enter both scenarios in this calculator to compare.
What is included in the monthly payment shown here?
This calculator shows principal and interest (P&I) only. It does not include property taxes, homeowners insurance, PMI, or HOA dues. Your actual total monthly housing payment will be higher. Check your lender's Loan Estimate for the full PITI estimate.
Compare Full Lender Offers Side by Side
The main RefinanceUSA calculator lets you compare multiple lender offers — rate, term, fees, and break-even — all in one view with a clear winner recommendation.
Open the Full Calculator