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Reficalc

The complete mortgage refinance guide

Last reviewed April 20, 2026 · RefiCalc editorial team

A mortgage refinance looks simple on the surface. Replace your old loan with a new one at a lower rate, lower the monthly payment, save money. Done. In practice, the math is trickier, the closing costs are bigger than people expect, and one of the most common refi scenarios saves you money every month while quietly costing you more over the life of the loan. This guide walks through the decision the way a financial planner would, with real numbers, named sources, and no lead-gen funnels.

If you want the calculator right now, it's on the home page. The math it runs is documented at the bottom of this page.

What break-even actually means (the two definitions)

Most refinance articles use "break-even" to mean one thing. There are really two, and the difference matters.

Definition 1: closing-cost recovery. The month when cumulative monthly savings from the new loan equal the closing costs you paid to refinance. If you save $300 a month and paid $6,000 in closing costs, you break even at month 20 (6000 divided by 300, rounded up). This is the number every calculator headlines. It's useful, but incomplete.

Definition 2: lifetime net impact. Total interest paid on the current loan over its remaining term, minus total interest on the new loan over its full term, minus closing costs. Positive means the refi saved money on net across the loan's life. Negative means you paid less per month but more in total because of the term extension. This is the number Bankrate, NerdWallet, and Rocket Mortgage bury in a collapsible panel or skip entirely.

Definition 1 tells you when the refi starts paying you. Definition 2 tells you whether, across the rest of your homeownership, it was the right call. You want both.

The term-extension trap (monthly win, lifetime loss)

Here's the scenario that trips up more homeowners than any other. You've been paying on a 30-year mortgage for five years. Balance is around $300,000 at 7%. You have 25 years remaining and you're paying roughly $2,120 a month in principal and interest. Rates drop to 6%. A refinance to a fresh 30-year at 6% takes your payment down to about $1,799. You save $321 a month. You feel like a hero.

Here's the receipt. Your old loan, at 25 remaining years, would have paid $336,000 in interest. Your new loan, at 30 years, will pay $347,500 in interest. Even at a lower rate, the five extra years of interest payments more than wipe out the rate drop. Add $6,000 in closing costs and you're $17,400 worse off across the life of the loan.

Month-to-month, it feels like a win. Calendar math says it wasn't. Our calculator flags this as "Maybe" instead of "Yes" and shows you exactly how many dollars the term extension costs.

Two ways to avoid the trap. Refinance into a shorter term if you can afford it (a 25-year refi keeps you on the same clock and captures the rate drop purely). Or, refinance into a 30-year at the new rate and manually make extra principal payments each month equal to what you'd pay on a 25-year. Same cash out of pocket, shorter real payoff. Either works. Just running a 30-year refi and pocketing the monthly savings is where people quietly lose.

Closing costs demystified

The CFPB says closing costs typically run 2 to 5 percent of the loan amount. On a $300,000 refi that's $6,000 to $15,000. The spread is wide because lenders bundle different fees, some roll them into the loan, and discount points are optional but common.

Here's what you'll see on page 2 of a Loan Estimate:

  • Origination charges. The lender's fee for processing the loan. Often 0.5% to 1% of the loan amount. Sometimes broken into application, underwriting, and processing fees. Negotiable with some lenders, fixed with others (Better.com advertises zero origination; Rocket Mortgage and LoanDepot typically charge 1%).
  • Discount points. Prepaid interest. One point equals 1% of the loan amount and buys the rate down by roughly 0.25%. Whether points are a good deal depends on how long you'll stay, run the numbers.
  • Services you cannot shop for. Appraisal ($500–$700 typical), credit report ($20–$50), flood certification, tax monitoring.
  • Services you can shop for. Title insurance (lender's policy required, owner's usually optional on a refi), escrow/settlement services, survey.
  • Taxes and government fees. Recording charges, transfer taxes if your state has them.
  • Prepaids and escrow. Prepaid interest from closing to your first payment, homeowners insurance for the year, property tax reserve. These are not refinance costs per se, but they are cash you'll bring to closing.

Ask each lender for the Loan Estimate itemized to those categories. The CFPB required a standardized format in 2015 specifically so borrowers could compare apples to apples. Use it.

The rate-drop-needed myth

You'll hear "you need at least a 1 percent rate drop to refinance." You'll also hear "0.5 percent is enough." Both are wrong in the strict sense. The right answer is arithmetic.

Whether a refi makes sense depends on three variables: rate change, closing costs, and how long you stay. A 0.25% drop with zero closing costs and a long stay can make sense. A 2% drop with high closing costs and plans to sell in a year does not. Stop looking for the magic threshold. Run the calculator.

That said, the rule-of-thumb 0.75% drop is roughly where most middle-of-the-road refis (average closing costs, plans to stay 5 to 10 years, 30-to-30 term swap) start paying off on a lifetime basis. Below that, the math usually does not work. Above, it often does.

Cash-out refinance is a different animal

A rate-and-term refi changes your rate and/or term without increasing the balance. A cash-out refi replaces your old loan with a bigger one and hands you the difference in cash. Both are technically refinances. They behave very differently.

Cash-out rates run 0.25% to 0.5% higher than rate-and-term, closing costs are similar or slightly higher, and the loan is larger so interest accrues on more principal. Fannie Mae limits cash-out LTV to 80% on most conventional loans. VA allows up to 100% on a VA cash-out for eligible veterans.

When cash-out works: you're consolidating high-interest debt (credit cards at 22% into a mortgage at 7% is a real savings), paying for a home improvement that adds value, funding a major life event where the alternative is a personal loan at 12%+. When it doesn't: funding lifestyle spending, paying off student loans that had a lower rate than your new mortgage, or chasing an investment you'd never make with cash.

Our calculator handles rate-and-term. Cash-out scenarios need a HELOC-vs-cash-out comparison, which we'll add in a future update.

Rate-and-term refinance: the pure play

This is the classic refi. Same loan balance, new rate, new term. The math is what the calculator runs. No surprises as long as you're honest about the term you're committing to and the stay horizon you really have.

The cleanest rate-and-term move is a same-term refi. If you have 22 years left and you refinance into a 22-year (or 20-year, rounding down), you capture the rate drop without the extension penalty. Most lenders will do custom terms; ask. If not, a 20-year is close enough and usually available at every lender from Chase to Wells Fargo to Fannie Mae's standard product mix.

ARM vs fixed after a refi

Adjustable-rate mortgages (ARMs) typically start 0.5% to 1% below a comparable fixed rate. They adjust after a fixed period (5, 7, or 10 years, the "5/6" and "7/6" ARMs being most common, the second number is how often the rate adjusts after the initial fixed period).

Refinancing from an ARM about to reset into a fixed-rate loan is often a very good idea, especially when fixed rates are near or below the ARM's current rate. Refinancing from a fixed into an ARM is the opposite bet, you're trading certainty for a lower rate in the short term. Only makes sense if you are confident you'll sell or refinance again inside the ARM's fixed period.

When a refi is always a no

Three scenarios where we'd walk away every time:

  1. You plan to sell the home within six months. Closing costs will never recover. Even a 2% rate drop can't save a sub-year horizon.
  2. Your break-even is longer than your realistic stay horizon. Selling at month 42 when break-even is month 48 means you paid the closing costs for nothing.
  3. The lender is charging closing costs above the CFPB's 5% top end with no itemized justification. Something is wrong with the loan. Walk.

When a refi is almost always a yes

Three scenarios where the math reliably wins:

  1. A 0.75%+ rate drop, you're staying 5+ years, and closing costs are inside the 2–3% band.
  2. Refinancing into a shorter term you can afford (from 30 to 15, or 25 to 20). Lifetime interest savings are usually six figures on a typical loan balance.
  3. Eliminating PMI by refinancing out of an FHA loan into a conventional once you have 20% equity. PMI on FHA is permanent for most new loans; conventional PMI drops off at 20% equity automatically.

The formula this calculator uses

Standard closed-form amortization. No simulation, no Monte Carlo, nothing fancy. Every mortgage textbook and the CFPB's own teaching materials use the same equation.

Monthly payment M, where P is principal, r is the monthly rate (annual divided by 12), and n is total number of monthly payments:

M = P × (r × (1 + r)^n) / ((1 + r)^n − 1)

Total interest paid is M × n − P. Break-even month is closing costs divided by monthly savings, rounded up. Lifetime net is current loan's remaining interest minus new loan's total interest minus closing costs.

We validated outputs against Bankrate's refinance calculator to the dollar across multiple scenarios. We round break-even up, not down, because costs are not fully recovered in the middle of a month. Bankrate does the same. NerdWallet rounds down, which is a minor but real difference.

Authority sources we trust

Every number and range in this guide ties back to a primary source. For mortgage math, the honest ones are:

We do not cite rate comparison sites as primary sources. We do not accept lender marketing as math. If you want to sanity-check our numbers against another honest calculator, Bankrate and NerdWallet are the best two. Our outputs will match theirs to the dollar on identical inputs, modulo the ceil-vs-floor break-even convention.

Ready to run your numbers?

Head back to the calculator and plug in your current loan and the quoted new terms. The break-even month, lifetime net, and verdict chip will tell you in seconds what most homeowners take a week of spreadsheeting to figure out. Got a scenario the calculator doesn't handle yet? Send it over. We read every note.