Finance category
Mortgage, loan, investing, tax, and money calculators.
Rate Lock Fallout Calculator
When market rates drop after a rate lock, borrowers face a tough decision: honor the lock and overpay, pay an extension fee while waiting, or 'fall out' (let lock expire and re-apply at lower rate). This calculator computes the monthly overpayment, lifetime cost, and extension fee so the right choice becomes clear.
Locked vs market rate gap %
0.63%
Monthly P&I overpayment
$208
Lifetime overpayment if held
$75,000
Extension fee per 30 days
$1,000
Recommendation
Worth fallout — re-lock
How the math works
Rate lock fallout: when market rates drop after you've locked, borrowers face a choice — stay locked (overpaying), pay extension fee while waiting for market improvement, or 'fall out' (let lock expire) and re-apply at lower rate (with re-application fees and timeline reset).
Lender lock fallout rate runs 15-25% historically. Lenders price float-down options into pricing because so many borrowers fall out anyway.
EveryCalc calculators are designed for fast, practical estimates with transparent inputs and no required account. We use plain formulas, visible assumptions, and related tools so visitors can check the result from more than one angle.
Results are informational only. For financial, tax, legal, medical, construction, or other high-impact decisions, verify the output against primary sources or a qualified professional.
Learn more about our review process on the EveryCalc methodology page.
How this calculator works
What this page estimates
This Rate Lock Fallout Calculator is built to give a quick, browser-based estimate for rate lock fallout. When market rates drop after a rate lock, borrowers face a tough decision: honor the lock and overpay, pay an extension fee while waiting, or 'fall out' (let lock expire and re-apply at lower rate). This calculator computes the monthly overpayment, lifetime cost, and extension fee so the right choice becomes clear. The inputs stay on the page during normal use, and the result should be treated as an estimate for planning, comparison, or education rather than professional advice.
Calculation approach
The calculator applies the standard relationship implied by the inputs, then formats the answer so it can be checked and reused. For finance tools, the most important step is using consistent units, rates, time periods, and assumptions before comparing the result with another calculator or outside quote.
Example workflow
For example, start with a realistic value you already know, change one input at a time, and watch how the answer moves. That makes it easier to tell whether the result is being driven by the main amount, the rate, the time period, or a unit conversion.
Practical checks
- Use current, real-world numbers when the result affects money, health, tax, or legal decisions.
- Run a low, base, and high case when the inputs are estimates.
- Check the related calculators below when the next decision depends on a different assumption.
How to interpret the rate lock fallout result
Best use
Use the result as a planning number for comparing payments, rates, returns, tax reserves, or cash-flow choices before you request a quote or make a commitment.
Cross-check
Compare the answer with the contract, lender estimate, tax form, brokerage statement, payroll record, or invoice that will control the real-world outcome.
Watch for
Do not rely on a single optimistic rate, return, or fee assumption. Money pages work best when you run low, base, and high cases and keep professional advice separate from the estimate.
This page belongs to the Finance calculator library, so the answer should be read in the context of the decision you are modeling rather than as a universal rule.
Before relying on this rate lock fallout estimate
Most calculator mistakes come from the inputs, not the arithmetic. Use this short audit before you reuse the answer in a spreadsheet, quote, application, or important conversation.
Confirm source numbers
Match balances, rates, fees, taxes, income, and payment dates against the lender quote, payroll record, tax form, statement, invoice, or contract.
Separate cash flow from total cost
A lower monthly payment can still cost more over time if fees, interest, taxes, or a longer term are hidden in the structure.
Run conservative cases
Test at least one higher-cost or lower-return case before using the output for a purchase, refinance, investment, loan, or tax decision.
Rerun this page when the rate, price, term, fee, tax rule, income, expense, or expected holding period changes.
How to Use
- Enter locked loan amount and locked rate.
- Enter current market rate and days until lock expires.
- Enter extension fee per 30 days %.
- Read rate gap, monthly overpayment, lifetime cost, and recommendation.
Frequently Asked Questions
When does fallout make sense?
Generally when rate gap exceeds 0.50%. Below that, extension fee or simply staying locked is usually cheaper than re-application timeline reset.
Re-application timing?
Re-apply at lower rate adds 30-45 days for new lock + processing. If purchase contract has tight close, may not be feasible.
Lender float-down option?
Many lenders include a one-time float-down at 0.25-0.50% fee. Often cheaper than fallout. Ask your loan officer at lock time.
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