Should I Refinance My Mortgage? Break-Even Analysis Explained

Mortgage rates dropped. Your inbox is full of mailers from lenders. Should you refinance? The answer depends almost entirely on one number: how long will you stay in the home? Refinancing has upfront costs, and if you move before recovering those costs in monthly savings, you lose money.

What refinancing actually is

Refinancing means replacing your existing mortgage with a new one, typically to:

• Lower your interest rate (rate-and-term refinance)
• Change your loan term (shorter term = pay off faster and save interest; longer term = lower monthly payment)
• Access home equity (cash-out refinance)
• Remove PMI (if you now have 20% equity and your original loan had PMI)
• Switch from variable to fixed rate (or vice versa)

Each refinance requires going through a new mortgage application, appraisal, title search, and closing. This takes 30–60 days and costs money.

Closing costs: the hurdle you must clear

Typical refinancing closing costs in the US: 2–5% of the loan balance. On a $300,000 loan, that's $6,000–$15,000. Some lenders offer "no-closing-cost" refinances — but these costs are simply rolled into the rate (slightly higher) or added to the loan balance. There's no free refinance.

Common components:

• Loan origination fee: 0.5–1.5% of loan amount
• Appraisal: $300–$600
• Title insurance: $500–$2,000
• Settlement/attorney fees: $500–$1,500
• Prepaid interest: varies by closing date
• Government recording fees: $50–$250

In the UK, refinancing (remortgaging) closing costs are typically lower — often £500–£2,000 for legal fees and valuation — but product fees charged by the new lender can be £999–£2,000 or more on some fixed-rate deals. Always compare the total cost including the product fee, not just the headline rate.

The break-even calculation

The simple break-even:

Break-even months = Closing costs ÷ Monthly savings

Example

Current loan: $320,000 remaining at 7.0%, 27 years left. Monthly P&I: $2,159.
New loan: $320,000 at 5.75%, 27 years. Monthly P&I: $1,946.
Monthly saving: $213.
Closing costs: $8,000.
Break-even: $8,000 ÷ $213 = 37.6 months — just over 3 years.

If you plan to stay in the home at least 4 more years, this refinance makes sense. If you're likely to move in 2 years, it does not.

The complication: changing your term

The simple break-even ignores one important factor: if your new loan resets to a longer term, you're extending your debt even if your payment is lower. Refinancing a 27-year remaining mortgage into a new 30-year mortgage gives you a lower payment but costs you 3 extra years of interest.

In the example above, taking a new 30-year loan at 5.75% (instead of matching the 27-year remaining term):

• Monthly P&I: $1,867 (lower payment, saves $292/month)
• Break-even on closing costs: 8,000 ÷ 292 = 27 months — looks better!
• But: you pay 3 extra years of interest on $320,000, adding roughly $67,000 in total lifetime interest

Always compare the total interest paid over the life of each loan, not just the monthly payment difference. A true apples-to-apples comparison uses the same remaining term on the new loan.

The true break-even (net present value approach)

The simple break-even ignores the time value of money. A more accurate approach: calculate the net present value of the stream of savings vs. the upfront cost. At typical discount rates (matching the opportunity cost of your cash), the NPV break-even is usually within a few months of the simple break-even, but it can differ meaningfully for large closing costs or long time horizons.

For most homeowners, the simple break-even is a sufficient decision tool.

When does refinancing clearly make sense?

• Rate drops of 1%+ and you're staying 5+ years. The traditional "1% rule" is a useful heuristic, though even 0.5% can pencil out on large loan balances with low closing costs and a long stay.
• You can afford to shorten the term. Refinancing from a 30-year to a 15-year at a lower rate saves massive amounts of interest. The higher monthly payment is the only downside.
• Removing PMI. If you've reached 20% equity and are still paying PMI, a new appraisal and refinance (or simply requesting cancellation with your current lender, which may not require a full refinance) removes the cost.
• Switching from adjustable to fixed. If your ARM is about to reset upward and you plan to stay long-term, locking in a fixed rate eliminates rate uncertainty.

When refinancing doesn't make sense

• You're close to paying off the mortgage. In the later years of a loan, most of each payment is principal — refinancing to a new long-term loan front-loads interest again.
• You're planning to sell soon. If you'll move before breaking even, the closing costs are a pure loss.
• Your credit score has dropped significantly since origination. A lower credit score may mean you can't access the best rates — your new rate could be similar to or worse than your existing rate.
• You just refinanced recently. Refinancing costs stack up; refinancing every time rates tick down 0.25% is usually not worth it.

Cash-out refinancing

A cash-out refinance lets you borrow more than your existing mortgage balance, receiving the difference in cash. If your home is worth $500,000 and you owe $250,000, a cash-out refinance to $350,000 gives you $100,000 in cash (minus closing costs).

Uses: home renovation, debt consolidation, investment. Risks: you're increasing secured debt on your primary residence. If property values fall or your income drops, you could end up underwater. Cash-out refinancing at the top of a rate cycle (borrowing at a high rate) can be particularly costly.

In the UK, this is called a "further advance" or "remortgage to release equity." Similar considerations apply.

The refinancing decision in practice

1. Get current rates from 3+ lenders (online, credit unions, your existing lender — who may offer a loyalty rate)
2. Estimate closing costs for each option
3. Calculate monthly savings at the new rate (matching your existing remaining term)
4. Divide closing costs by monthly savings to get the break-even in months
5. Compare to your realistic time horizon in the home
6. If break-even is comfortably within your horizon, refinance