Rate Lock Extension Cost Calculator

Rate lock extensions carry daily or tiered fees. This calculator sizes cost.

Loan amount

Extension days

Daily fee (bps)

Rate bump (bps)

Loan term years

Total extension cost

$583,000

Upfront fee

$33,000

Lifetime interest bump

$550,000

How the math works

Upfront = loan × daily bps × days. Lifetime interest bump = loan × rate bump × years.

Small bps adjustments at extension compound over 10-year terms. A 25 bps rate bump on a $22M loan costs $55k annually and $550k across a 10-year hold — more than most extension fee schedules, but often overlooked because the headline fee is small.

How to Use

Enter loan amount.
Enter extension days.
Enter daily fee bps.
Enter rate bump bps at extension.
Enter loan term years.
Read total extension cost.

Frequently Asked Questions

Typical fees?

Daily extension: 0.125-0.5 bps per day beyond original lock. Tiered: 15/30/45 day extensions at 25/50/100 bps. Major cost driver on delayed closings — construction loans most exposed.

When extensions happen?

Construction delay pushes closing past lock. Third-party reports (appraisal, environmental, title) take longer than expected. Legal or document delay. Each common reason for 15-60 day extensions.

Mitigation?

Extend lock preemptively (cheaper than emergency). Lock later in process. Use float-down options. Negotiate free extensions up front (some lenders offer 30-60 days built-in). Each reduces extension cost.

How does this interact with the rest of the capital stack?

Each tier of the stack affects the next. Senior debt constrains LTC and DSCR. Mezz and pref consume equity spread. Interest rate hedges protect DSCR but cost premium. Always model the full stack holistically — optimizing one tier alone often degrades another. Institutional underwriters run three or four scenarios across the stack before committing capital.