Forget the 2% Rule

You've probably heard "refinance when rates drop 2% below your current rate." This rule of thumb is too simplistic. A 1% rate drop on a $400,000 loan saves much more than a 2% drop on a $150,000 loan. The dollar amount matters more than the percentage.

The Real Question: Break-Even

Refinancing costs money — typically 2-5% of the loan amount in closing costs. The question isn't "is the new rate lower?" — it's "how many months until my monthly savings pay back the closing costs?"

Break-even months = closing costs / monthly savings

If refinancing costs $8,000 and saves you $200/month, your break-even is 40 months. If you plan to stay in the home for at least 40 more months, refinancing makes financial sense.

When Refinancing Makes Sense

Your break-even is well within your expected stay. If you plan to stay 10 more years and break-even is 30 months, that's 7+ years of pure savings.

You're resetting to a shorter term. Refinancing from a 30-year into a 15-year at a lower rate can save enormous amounts of interest — even if the monthly payment goes up.

You're eliminating PMI. If your home has appreciated and you now have 20% equity, refinancing can drop PMI entirely — a savings of $100-300/month on most loans.

When It Doesn't Make Sense

You're far into your current loan. If you're in year 20 of a 30-year mortgage, most of your payment is already going to principal. Restarting a 30-year clock means paying more interest overall, even at a lower rate.

Your break-even exceeds your time horizon. If you might sell in 2 years and break-even is 3 years, you lose money.

The rate difference is small and the loan balance is low. Saving 0.5% on a $120,000 remaining balance might save $50/month — not worth $6,000 in closing costs.

Model It Yourself

Use the Refinance Calculator or load the Refinance Comparison template to see a pre-built before/after scenario. The What-If Lab also lets you model a refinance on any existing scenario without creating a new one.