Mortgage Rate Lock Calculator

Should you lock your rate now or float? This critical decision can save or cost you $10,000+ over 30 years. Get instant analysis.

3 scenario analysis
Risk-based recommendations
30-year cost impact
Expert timing advice
⚠️

Don't Lock Without Comparing Rates First!

Before you lock, make sure you're getting the best rate. Compare offers from 300+ lenders and save thousands.

Mortgage Rate Lock Calculator

Should you lock your rate now or float? Make the right decision.

Fee: $0

RECOMMENDATION

LOCK SOON - Moderate risk, secure your rate within 7-10 days

📊 Rate Movement Scenarios

Here's what could happen if you don't lock your rate today:

📈 Worst Case

Rates increase 0.25%

New Rate

7.25%

Monthly Payment

$2,728.705

Cost vs Locked

+$67.495/mo

30-Year Cost

+$24,298.25

➡️ Most Likely

Rates stay the same

New Rate

7%

Monthly Payment

$2,661.21

Cost vs Locked

$0/mo

30-Year Cost

$0

📉 Best Case

Rates decrease 0.25%

New Rate

6.75%

Monthly Payment

$2,594.392

Savings vs Locked

-$66.818/mo

30-Year Savings

-$24,054.334

💡 Rate Lock Strategy Tips

✅ Lock Your Rate If:

  • • Rates are trending upward
  • • You're 30-45 days from closing
  • • You're risk-averse
  • • Fed is raising rates
  • • You found a great rate

⚠️ Consider Floating If:

  • • Rates are trending downward
  • • You're 60+ days from closing
  • • You're comfortable with risk
  • • Fed is cutting rates
  • • Lock fees are high

🎯 Ready to Lock Your Rate?

Get quotes from multiple lenders before locking. Compare rates, lock periods, and fees to ensure you're getting the best deal.

Understanding Mortgage Rate Locks

What is a Rate Lock?

A mortgage rate lock is a guarantee from your lender that your interest rate won't change between your offer and closing, as long as you close within the lock period (typically 30-60 days). This protects you from rate increases but also prevents you from benefiting if rates drop.

Example: You lock a 7.0% rate on a $400,000 loan. Even if rates jump to 7.5% before closing, you still get 7.0%. But if rates drop to 6.5%, you're stuck at 7.0% (unless you have a float-down option).

When Should You Lock Your Rate?

✅ Lock Your Rate If:

  • Rates are rising: Fed is raising rates or market trends upward
  • 30-45 days to close: Optimal timing to lock
  • You're risk-averse: Peace of mind is worth it
  • Great rate offered: Below market average
  • Economic uncertainty: Inflation, geopolitical events

⚠️ Consider Floating If:

  • Rates are falling: Fed is cutting rates or downward trend
  • 60+ days to close: Too early to lock (extension fees)
  • You're risk-tolerant: Willing to gamble for savings
  • High lock fees: 0.25-0.5% of loan amount
  • Float-down option: Can lock later if rates drop

Rate Lock Periods Explained

Lock PeriodTypical FeeBest ForRisk Level
15 daysFree - 0.125%Quick closes, refinances⚠️ High
30 daysFree - 0.125%Standard purchases⚖️ Medium
45 days0.125% - 0.25%New construction, contingencies✅ Low
60 days0.25% - 0.375%Complex transactions✅ Very Low

Frequently Asked Questions

What happens if I don't close in time?

If you don't close within your lock period, you'll need a rate lock extension (typically 0.125-0.25% per 15 days) or re-lock at current market rates. This can be expensive, so choose a lock period with buffer time.

Can I lock my rate before finding a home?

No, you need a purchase contract to lock a rate. However, you can get pre-approved and receive a rate quote. Some lenders offer "early rate locks" once you're under contract, even before appraisal.

What is a float-down option?

A float-down allows you to lock your rate but still benefit if rates drop significantly (typically 0.25%+) before closing. This costs 0.125-0.25% upfront but gives you the best of both worlds. Not all lenders offer this.

How much does a 0.25% rate increase cost?

On a $400,000 loan, a 0.25% rate increase (7.0% to 7.25%) costs about $70/month or $25,000+ over 30 years. This is why timing your rate lock is so critical.

Should I pay for a longer lock period?

Only if necessary. A 60-day lock costs 0.25-0.375% ($1,000-$1,500 on $400K loan). If you're confident you'll close in 30-45 days, save the money. If there are delays (appraisal, inspection), the longer lock is worth it.