Rate Lock Float-Down 2027 Calculator
A float-down rate lock lets you lock today's rate but accept a lower one if rates drop during the lock period. Comes with a fee (0.25-0.75% of loan). Decide if the fee is worth potential savings. Source: CFPB lock-period guidance.
How a Float-Down Lock Works
Standard 30-60 day rate lock guarantees your rate at application time. If rates drop before closing, you're stuck. Float-down lock adds the option: if rates drop ≥0.25% by closing, you can re-lock at the lower rate, paying a one-time fee (0.25-0.75% of loan). Useful in declining-rate environments or for long lock periods (60-90 days). Source: CFPB.
Break-Even Math
Fee of 0.50% on $400,000 = $2,000. To recover via lower monthly payment, you need rates to drop enough that 30-year savings exceed $2,000. At $400k loan, a 0.10% rate drop saves ~$25/month × 360 = $9,000 over loan life. So you need just 0.025% drop to break even on the fee — generous! Most float-downs trigger if rates drop ≥0.25%, well above break-even.
When Float-Down Makes Sense
(1) Long lock period (60-90 days, common for construction or contingencies). (2) Declining-rate environment (Fed cutting cycle). (3) Volatile markets. Skip the float-down for 30-day locks in stable markets — fee likely wasted. Always compare total cost including lock extension fees if you exceed lock period.
Alternative: Renegotiate or Switch Lenders
Some lenders allow re-locking once for free if rates drop significantly (relationship pricing). If yours doesn't, switching lenders mid-process is possible but adds cost (appraisal, credit pull, fees ~$1k). Float-down typically cheaper than switching lenders if drop is moderate.
Frequently Asked Questions
What is a float-down rate lock?
An optional add-on to a standard rate lock that lets you accept a lower rate if market rates drop before closing. Fee typically 0.25-0.75% of loan.
Is a float-down lock worth it?
Yes in declining-rate environments or for 60-90 day locks. Break-even rate drop is typically very small (~0.025%) for a 0.50% fee on a 30-year mortgage.
Can I re-lock for free?
Some lenders offer one free re-lock as relationship pricing. Ask before paying for float-down.
How much does a 0.10% rate drop save?
On a $400k 30-year loan, 0.10% drop saves about $25/month, totaling $9,000 over the loan life. Significant relative to a $2,000 float-down fee.
Should I switch lenders if rates drop?
Switching costs $1,000-2,000 in re-application fees and adds 2-4 weeks. Float-down is usually cheaper unless rates drop more than 0.50%.