Interest Rate Comparator
Compare two loans side by side. See which rate saves you more — in monthly payments, total interest, and total cost.
| Metric | Loan A | Loan B | Difference |
|---|---|---|---|
| Interest rate | — | — | — |
| Monthly payment | — | — | — |
| Total interest paid | — | — | — |
| Total cost | — | — | — |
Even a small difference in interest rate can cost you thousands of dollars over the life of a loan. On a $30,000, 5-year loan, the gap between 6.5% and 8.9% means paying over $2,000 more in interest — for the exact same loan.
Lenders quote APR (Annual Percentage Rate) — compare this number directly. A lower APR always means lower total cost when the loan amount and term are equal.
Disclaimer: This interest rate comparator is for educational and informational purposes only. Results assume fixed interest rates, equal loan amounts, and equal terms. Actual loan costs may include fees, penalties, or variable rates not reflected here. This is not financial advice. Always read the full loan agreement before signing.
How to use this interest rate comparator
Enter the same loan amount and term for two different interest rates. The calculator shows you the difference in monthly payment and total cost — so you can see exactly what a lower rate is worth in real dollars.
Use this when comparing offers from different lenders, deciding whether to refinance, or evaluating whether a rate buy-down (paying points upfront to lower your rate) is worth the cost.
What a 1% rate difference actually costs
On a $300,000 30-year mortgage, the difference between 6.5% and 7.5% is approximately $190/month — or $68,000 over the life of the loan. On shorter loans, the monthly difference is smaller but the total interest impact is still significant.
Even half a percent matters. A 0.5% rate difference on a $400,000 mortgage saves approximately $45,000 in total interest over 30 years. This is why it is worth getting quotes from at least 3 lenders and negotiating — even a small rate improvement has a large long-term impact.
When to use this for refinancing decisions
Compare your current rate against the rate you have been offered. Then calculate your break-even: divide your refinancing closing costs by the monthly savings. If closing costs are $4,000 and you save $200/month, your break-even is 20 months. If you plan to stay in the home longer than that, refinancing makes financial sense.
Also use this tool when considering whether to pay mortgage points. One point (1% of the loan amount) typically lowers your rate by 0.25%. On a $300,000 loan, one point costs $3,000. If that drops your rate from 7.0% to 6.75%, use this calculator to see how many months it takes to recoup that cost through lower payments.
Real-world scenarios: what rate differences actually cost
The numbers below are calculated using standard amortisation. Use them as a reference point when you get competing loan offers — then plug your exact numbers into the comparator above for a precise figure.
Personal loan — $15,000 over 5 years
| Interest Rate | Monthly Payment | Total Interest | Total Cost |
|---|---|---|---|
| 8% | $304 | $2,240 | $17,240 |
| 12% | $333 | $3,999 | $18,999 |
| 18% | $381 | $7,860 | $22,860 |
| 24% | $432 | $10,912 | $25,912 |
Mortgage — $350,000 over 30 years
| Interest Rate | Monthly Payment | Total Interest | Total Cost |
|---|---|---|---|
| 5.5% | $1,987 | $365,320 | $715,320 |
| 6.5% | $2,212 | $446,220 | $796,220 |
| 7.0% | $2,329 | $488,440 | $838,440 |
| 7.5% | $2,447 | $531,060 | $881,060 |
The difference between 5.5% and 7.5% on a $350,000 mortgage is $460 per month and over $165,000 in total interest. That is why spending an extra week shopping lenders and improving your credit score before applying is one of the highest-return actions available to a home buyer.
How your credit score affects the rate you are offered
Lenders use your credit score as the primary signal for pricing risk. The rate tiers below are approximate industry benchmarks for personal loans — mortgage rates follow a similar pattern but with narrower bands:
| Credit Score | Rating | Typical Personal Loan APR |
|---|---|---|
| 720–850 | Excellent | 7–12% |
| 680–719 | Good | 12–17% |
| 640–679 | Fair | 17–24% |
| 580–639 | Poor | 24–36% |
Moving from "fair" to "good" credit can reduce your personal loan APR by 7–12 percentage points. On a $15,000 loan over 5 years, that translates to roughly $4,000–$6,000 in interest savings. If your score is borderline, delaying a loan application by 3–6 months to improve your credit first can be worth more than any lender negotiation.
Rate vs term: the trap most borrowers miss
A lower monthly payment is not the same as a better deal. Extending a loan term reduces monthly payments but dramatically increases total interest paid — even at the same rate.
Example: $20,000 personal loan at 10% APR:
- 3-year term: $645/month — total interest $3,226
- 5-year term: $425/month — total interest $5,496
- 7-year term: $332/month — total interest $7,869
Choosing the 7-year term over the 3-year to get a lower monthly payment costs an extra $4,643 in interest — despite the rate being identical. When comparing loans, always look at total cost alongside monthly payment. The comparator above shows both, so you can make the decision with full information.
When to get multiple loan quotes — and how many
Research consistently shows that borrowers who get only one quote pay significantly more than those who shop around. The Consumer Financial Protection Bureau found that borrowers who get just one additional mortgage quote save an average of $1,500 over the loan term. Getting five quotes saves around $3,000.
Practical guidance: get at least 3 quotes from different lender types — your primary bank, a credit union, and an online lender. Each uses different underwriting models and pricing strategies, so the variation between them is often larger than most borrowers expect.
For mortgages, multiple hard inquiries within a 14–45 day window are treated as a single inquiry by the major credit bureaus for scoring purposes — so shopping aggressively within that window does not meaningfully impact your score.
Why a Small Rate Difference Matters More Than You Think
A 1% difference in interest rate might seem trivial, but on a $20,000 car loan over 5 years, it adds up to hundreds of dollars. On a $300,000 mortgage over 30 years, a 0.5% rate difference can mean over $30,000 in extra interest.
Use this calculator to compare any two loan rates side by side. Enter the same loan amount and term for both, then adjust the rates to see your exact monthly payment difference and total interest savings.
When to Use This Calculator
This tool is useful when you're comparing loan offers from two different lenders, deciding whether to refinance, or evaluating the impact of improving your credit score before applying. A higher credit score typically qualifies you for a lower rate — use our calculator to quantify exactly what that improvement is worth in dollars.