Mortgage rate change calculator
Compare two user-entered note rates on the same fixed-rate loan. See the estimated change in principal and interest. Your numbers stay on this device.
Compare rates
Note rates, not APRs.
Example comparison
A 0.25 percentage point increase
$66.12 more / month
$793.44 more per year
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- Rate difference
- +0.25 pp (+25 basis points)
- Starting payment
- $2,528.27
- Comparison payment
- $2,594.39
- Estimated annual change
- $793.44 more
- Same-payment loan amount
- $389,806
- Loan-amount difference
- $10,194 less
Educational estimate only. This tool does not provide a loan offer, approval, qualification decision, payoff statement, servicing record, tax advice, legal advice, or individualized financial advice. Results depend on the assumptions entered and may differ from lender, servicer, insurer, tax authority, HOA, or closing documents.
Excludes taxes, insurance, mortgage insurance, HOA dues, points, closing costs and lender pricing.
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Payment impact by rate change
See the same loan and term across standard percentage-point changes.
| Change | Resulting rate | Monthly P&I | Monthly difference | Annual difference |
|---|---|---|---|---|
| −1 pp | 5.5% | $2,271.16 | −$257.12 | −$3,085.39 |
| −0.5 pp | 6% | $2,398.20 | −$130.07 | −$1,560.84 |
| −0.25 pp | 6.25% | $2,462.87 | −$65.40 | −$784.84 |
| −0.125 pp | 6.375% | $2,495.48 | −$32.79 | −$393.51 |
| 0 pp | 6.5% | $2,528.27 | $0.00 | $0.00 |
| +0.125 pp | 6.625% | $2,561.24 | +$32.97 | +$395.66 |
| +0.25 pp | 6.75% | $2,594.39 | +$66.12 | +$793.44 |
| +0.5 pp | 7% | $2,661.21 | +$132.94 | +$1,595.25 |
| +1 pp | 7.5% | $2,796.86 | +$268.59 | +$3,223.03 |
Same-payment loan amount
At 6.75%, the same $2,528 monthly principal-and-interest payment corresponds to an estimated $389,806 loan over 30 years—$10,194 less than at 6.5%.
This is a mathematical loan-amount comparison, not an affordability, approval, qualification, or home-price estimate. Down payment and ownership costs are excluded.
How rate impact is calculated
Each payment uses the same loan amount and term with a different user-entered note rate. The monthly difference is the comparison payment minus the starting payment.
The same-payment loan amount inverts the unrounded principal-and-interest payment through the same engine formula.
Check the calculation and sourcesWorked example
$300,000 loan 30 years
6.00% starting note rate 6.50% comparison
- Starting principal and interest
- $1,798.65
- Comparison principal and interest
- $1,896.20
- Monthly change
- $97.55 more
- Annual change
- $1,170.63 more
Illustration only—not a lender quote, APR or available offer.
Assumptions and limitations
The comparison holds loan amount and term constant and models level-payment fixed-rate principal and interest from payment one. It does not model refinancing costs, term resets, points, taxes, insurance, qualification or lender pricing.
Read the rate-impact methodologyReview formulas and primary sources Read the corrections policy
Mortgage rate-change questions
Is this comparison using APR?
No. It uses user-entered note rates. APR may also reflect certain borrowing costs.
Does a lower payment mean I qualify for a larger loan?
No. The same-payment loan amount is a mathematical comparison, not a qualification or affordability estimate.
Does this include taxes and insurance?
No. This focused tool compares principal and interest only. Use the mortgage calculator for broader housing-cost estimates.