Refi math: when the numbers actually work

The refinance industry runs on a comfortable lie: "Rates dropped, therefore you should refinance."

Nope. Sometimes yes, often no. The only thing that matters is whether the math actually works over your specific timeline. I've told clients not to refi more times than I can count — even when it cost me the commission — because the numbers didn't add up.

Here's exactly how I calculate whether a refi makes sense. Steal this framework. Use it on the next mailer that says "rates just dropped, save $500/mo!"

The only question that matters: break-even

Refinancing costs money. Real money — usually 2-5% of your loan amount in closing costs. For a $400K refi, that's $8,000-$20,000 out of pocket (or rolled into the loan, which just delays the pain).

So the only question is: how long until your monthly savings pay back what the refi cost you?

That's break-even. It's a division problem, not a marketing exercise.

A real example

Let's use round numbers. You have a $400,000 mortgage at 7.5%, 25 years left. Your current P&I payment is $2,957/month.

Rates drop, and I can refinance you to 6.25% on a new 30-year loan. Sounds great, right? Let's do the math.

The gotcha: term extension

Notice something in that example? We went from 25 years left on the current loan to 30 years on the new loan. That's five extra years of payments.

Over 30 years at $2,462/mo, you pay $886,320 total. On the original 25-year, $2,957/mo path, you'd pay $887,100. The lifetime cost is basically identical — you just paid the bank an extra 5 years of interest to lower your monthly.

Refinancing to a longer term is a cash-flow tool, not a savings tool. That's fine if you need the cash flow — but understand what you're actually doing.

The way to get real savings is to refinance to the same or shorter term. Let's redo the math.

The 0.75% rule of thumb

My general rule: don't bother refinancing unless you can drop your rate at least 0.75%. Below that, closing costs eat most of the benefit unless you're planning to stay in the house forever.

Some exceptions:

• You're eliminating PMI — dropping mortgage insurance can save you $150-400/mo. Even a small rate reduction plus PMI removal can be worth it.
• You're moving from ARM to fixed — if your ARM is about to adjust upward, locking in a fixed rate can be smart even at a slightly higher rate.
• Cash-out for high-value use — refinancing to pull cash out for a specific investment (renovations, debt consolidation) can pencil out even without a rate drop.

Cash-out refinancing — be careful here

Cash-out refis get pitched heavily because they generate huge commissions. Sometimes they make sense. Often they don't.

Cash-out refi makes sense when:

• You're consolidating high-interest debt (credit cards at 20%+) into a mortgage at 7%
• You're funding renovations that increase home value
• You're investing in something with a higher expected return than the mortgage rate

Cash-out refi does not make sense when:

• You're funding a vacation or discretionary spending
• You're consolidating credit card debt without changing the underlying spending habits (this is how people end up with a huge mortgage and maxed credit cards)
• You're extending your loan term significantly to fund something short-term

My honest recommendation checklist

Before you refinance, run through this. If you can't check every box, wait or ask more questions:

1. The new rate is at least 0.75% lower than current — OR you're removing PMI/ARM risk
2. Break-even is less than half the time you plan to stay in the house
3. You're refinancing to the same or shorter term (unless you specifically need lower cash flow)
4. You've compared at least 2-3 lenders' actual Loan Estimates (not just rate quotes)
5. You understand the total lifetime cost, not just the monthly payment

The best refinance is the one that saves you the most money over the shortest time. The worst refinance is the one that feels good today because your monthly payment dropped, but costs you $50K more over 30 years.

When to actually call me

The truth is, refinance math is genuinely complicated once you factor in your specific situation — current rate, remaining term, tax situation, plans to move, PMI status, and closing costs vary wildly.

The right approach is:

1. Bring me your current mortgage statement
2. Tell me why you're considering the refi
3. Let me run the real break-even for your situation
4. I'll tell you honestly whether it makes sense

Sometimes the answer is "yes, refi now." Sometimes it's "wait six months and see." Sometimes it's "don't refi — just make extra principal payments on your current loan." I'll tell you which one.

Thinking about a refi? Call or text 863-695-2265, or get a free refi analysis. Zero pressure, no credit pull for the initial review.