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.

Float-Down Worth It?
Required rate drop to break even
Float-Down Fee
Monthly Lock Payment
Savings per 0.10% drop
Break-Even Rate Drop
Worth It?
Cost of NOT Locking
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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.