Most borrowers pick the loan with the lowest rate and call it a day. That instinct is wrong more often than you think. A loan comparison calculator forces you to look at total cost: monthly payments over your actual hold period plus every upfront dollar in origination fees, points, and closing costs. A 6.75% loan with $11,000 in fees can easily cost more over seven years than a 7.125% loan with $3,500 in fees. Rate is one variable. Dollars out of your pocket is the only scoreboard that matters.
Why "lowest rate wins" is bad math
Rates get all the attention because they are easy to compare. But the rate on your loan estimate is just one of three cost drivers, and often not the largest one over a typical hold period.
- Origination fees and points are immediate costs. A lender offering 6.625% with 1.5 points on a $300,000 loan collects $4,500 at closing before you make your first payment. A second lender at 7% with zero points collects nothing. The lower-rate loan needs roughly 5 years of monthly savings ($75/month difference) just to break even on that $4,500.
- Closing costs vary by thousands. An investor in Phoenix pulling a conventional loan might pay $5,200 in closing costs. The same investor getting a DSCR loan on a rental in Memphis could face $9,800 in origination and lender fees. If both loans carry a 7% rate, the DSCR loan costs $4,600 more before a single payment is made.
- Hold period changes the winner. Total interest on a 30-year loan sounds terrifying until you realize most investors sell or refinance within 7 to 10 years. Over that window, upfront fees often matter more than a 0.25% rate difference.
The only honest comparison is total dollars spent over the time you actually expect to hold the loan. This loan comparison calculator does that math for you.
15-year vs. 30-year: the real tradeoff
The internet loves the 15-year mortgage. Pay less interest, build equity faster, own it sooner. All true. But the advice usually ignores what that higher payment prevents you from doing with your capital.
Take a $280,000 loan balance. Here is the side-by-side:
| 30-year at 7.25% | 15-year at 6.5% | |
|---|---|---|
| Monthly payment (P&I) | $1,910 | $2,439 |
| Total interest paid | $407,600 | $159,040 |
| Total cost (payments + closing) | $693,600 | $447,040 |
| Monthly difference | $529 more on the 15-year | |
| Interest saved with 15-year | $248,600 over the full term | |
On paper, the 15-year saves a quarter million in interest. That is real money. But it also locks $529/month into a single property. For an investor in Indianapolis buying rentals at $200,000, that $529/month is the gap between buying one property this year and buying two. If the second rental produces 8% cash-on-cash, the 30-year borrower is deploying capital at a higher total return than the 15-year borrower saving on interest.
Run the 15-year when it is your only property and you want it paid off. Run the 30-year when you are scaling a portfolio and every dollar of cash flow funds the next down payment.
Fixed vs. ARM: when adjustable rates make sense for investors
Fixed rates are the default because they are predictable. But adjustable-rate mortgages are not the reckless products they were in 2006. A 5/1 ARM gives you a fixed rate for five years, then adjusts annually. A 7/1 ARM gives you seven years.
The math is simple. In early 2026, a 30-year fixed on an investment property runs about 7.25% in markets like Dallas and Atlanta. A 5/1 ARM on the same property can come in at 6.25% to 6.5%. On a $320,000 loan:
- 30-year fixed at 7.25%: $2,183/month
- 5/1 ARM at 6.25%: $1,971/month
- Monthly savings: $212
- 5-year savings: $12,720
If you plan to sell or refinance before year five, you pocket $12,720 in savings with zero exposure to the rate adjustment. This is why fix-and-flip investors and BRRRR operators use ARMs routinely: their exit is baked into the strategy before the fixed window closes.
The risk is staying past the adjustment. If rates climb and you are still holding, your payment can spike $300 to $500/month depending on the adjustment caps. Know your exit timeline before choosing an ARM.
Conventional vs. DSCR: two different playing fields
These are not just two flavors of mortgage. They use entirely different underwriting, and the cost structures reflect that.
| Conventional (investment) | DSCR loan | |
|---|---|---|
| Typical rate | 6.75% to 7.50% | 7.25% to 8.25% |
| Origination | 0.5% to 1% | 1% to 2.5% |
| Down payment | 20% to 25% | 20% to 25% |
| Income docs | Full (tax returns, W-2s) | None (property income only) |
| Loan limit | 10 financed properties | No cap |
| Closing costs (typical) | $5,000 to $8,000 | $8,000 to $14,000 |
On a $300,000 loan, the rate and fee difference between conventional and DSCR can mean $3,000 to $8,000 more in year-one cost for the DSCR path. That gap is the price of skipping income verification. For an investor in San Antonio with a W-2 job and three financed properties, conventional is the obvious cheaper option. For a full-time investor in Jacksonville holding 12 rentals and no longer qualifying on DTI, DSCR is the only option, and the higher cost is the toll for continued growth.
Use the DSCR loan calculator to see how much a property's income supports, then come back here to compare the total cost against a conventional option.
How closing costs change which loan wins
Closing costs are the most overlooked variable in loan comparison because they feel like a sunk cost. You pay them once and forget. But they shift the total cost math more than most borrowers realize, especially over shorter hold periods.
Example: two loans on a $350,000 rental in Charlotte, North Carolina, both at $280,000 borrowed.
- Loan A: 6.875%, $10,500 in closing costs (includes 1 discount point)
- Loan B: 7.25%, $4,200 in closing costs (no points)
- Monthly payment difference: $71 lower on Loan A
- Upfront cost difference: $6,300 higher on Loan A
- Breakeven: $6,300 / $71 = 89 months (7.4 years)
If you hold for 10 years, Loan A saves about $2,240 total. If you sell at year 5, Loan B saves $2,040. The closing costs calculator can help you pin down the exact fees for each loan option. Plug those numbers in here and the breakeven becomes obvious.
The opportunity cost angle
Here is the part most loan comparisons skip entirely. Every dollar you commit to a higher monthly payment or larger upfront cost is a dollar that cannot work for you somewhere else. This matters less for homeowners, but it changes the math completely for investors.
Say you choose the 30-year loan over the 15-year and keep your monthly payment $529 lower. If you deploy that $529/month into a rental property earning 10% cash-on-cash, after 10 years that capital has grown to roughly $102,000 in cumulative returns and deployed principal. The 15-year loan saved $248,600 in interest over its full term, but that savings only materializes if you actually hold for 15 years and have no better use for the cash.
This is not an argument against 15-year loans. It is an argument for knowing your cost of capital. If you can earn more deploying that cash than you save on interest, the "expensive" 30-year loan is actually the cheaper option in portfolio terms.
Worked example: 30-year at 7.25% vs. 15-year at 6.5%
Same property, same $280,000 balance. Buyer in Columbus, Ohio. Let us trace the cost through three different hold periods to see how the winner changes.
| Hold period | 30-year total cost | 15-year total cost | Winner |
|---|---|---|---|
| 5 years | $114,600 + $6,000 closing | $146,340 + $8,000 closing | 30-year (by $33,740) |
| 10 years | $229,200 + $6,000 | $292,680 + $8,000 | 30-year (by $65,480) |
| Full term | $687,600 + $6,000 | $439,040 + $8,000 | 15-year (by $246,560) |
Notice the pattern. The 30-year wins on total payments made during any hold period shorter than the 15-year term because the monthly payment is simply lower. The 15-year only wins when you hold it to maturity, because the massive interest savings compound over the full 15 years. For an investor who refinances at year 7 to pull equity for the next deal, the 30-year cost less in actual dollars spent.
But "total payments made" is not the full story. The 15-year builds equity faster because more of each payment goes to principal. At the 10-year mark on the $280,000 loan, the 15-year borrower owes roughly $125,000 while the 30-year borrower still owes about $242,000. That $117,000 equity difference has value, especially if you are planning a cash-out refinance.
Points vs. no points: when buying down the rate pays off
Discount points let you prepay interest at closing to lower your rate. One point equals 1% of the loan amount and typically reduces the rate by 0.25%. The question is always the same: does the monthly savings recover the upfront cost before you sell or refinance?
On a $300,000 loan, one point costs $3,000. Dropping from 7.25% to 7% saves about $51/month. Breakeven: 59 months, just under five years. Two points cost $6,000 and drop you to 6.75%, saving $101/month total. Breakeven: still about 59 months because the savings scale linearly with the cost.
Points pay off in these situations:
- Long hold, stable rates. If you are buying a primary residence in Denver and plan to stay 10+ years, paying one point saves roughly $3,120 over and above the cost after the breakeven. That is a guaranteed return.
- Cash flow sensitivity. An investor in Milwaukee with tight margins on a rental might buy a point to push cash flow positive. The $3,000 upfront is worth it if the deal does not work without the lower payment.
Points do not pay off in these situations:
- Short holds. If you plan to sell or refinance within 3 to 4 years, you exit before breakeven. The point was a donation to the lender.
- Rates are expected to drop. If you expect to refinance when rates decline, the paid-down rate disappears with the old loan. You paid for a lower rate you did not keep.
- Capital constraints.If paying $3,000 to $6,000 in points means you cannot cover reserves or your next property's down payment, skip the points and keep your liquidity.
Common mistakes when comparing loans
These errors are not theoretical. They cost borrowers real money on real deals, and they show up in loan comparisons constantly.
- Comparing rate without term. A 6.5% 15-year loan and a 7.25% 30-year loan are not comparable on rate alone. The 15-year has a $529/month higher payment on a $280,000 balance. You are comparing two completely different cash flow profiles. Always match the comparison to your actual payment capacity.
- Ignoring closing costs in the total. Two lenders quote you the same rate. One charges $4,000 in closing costs, the other $9,500. That $5,500 gap is real money you spend on day one. Fold closing costs into the total cost or your comparison is incomplete.
- Assuming you will hold to maturity. The median homeowner stays 13 years. Investors hold rentals 7 to 10 years on average. If you run a 30-year total interest comparison but sell at year 8, you made the decision on data that does not apply to you. Always compare over your realistic hold period.
- Forgetting about PMI. A conventional loan with 10% down carries private mortgage insurance at 0.5% to 1% of the loan annually. On a $300,000 loan, that is $1,500 to $3,000/year until you hit 20% equity. A competing loan requiring 20% down has no PMI. If you compare the two loans on rate and ignore the PMI difference, the 10%-down option looks cheaper than it is.
- Comparing APR across different hold periods. APR amortizes upfront costs over the loan's full term. If you sell at year 5, the APR understates the true cost of a high-fee loan because you are paying those fees over fewer years. Use total cost over your hold period, not APR, for the final verdict.
- Not accounting for tax deductibility. Mortgage interest is deductible if you itemize (primary residence) or deductible as an expense (investment property). A higher-rate loan generates a larger deduction. On a rental in a 24% tax bracket, the after-tax cost of a 7.25% loan is effectively 5.51%. That narrows the gap between loan options and can flip which one is cheaper after taxes.
How to use this loan comparison calculator
Plug in two real loan offers, not hypothetical rates from a headline. Use the loan estimates your lenders provided. Set the loan amount, rate, term, and closing costs for each option. The calculator shows you total cost, monthly payment, total interest, and which loan wins on lifetime dollars.
A few ways to use it:
- Compare two lender quotes on the same property to pick the cheaper option.
- Run a 15-year vs. 30-year comparison at today's rates on your specific loan amount.
- Compare a conventional loan against a DSCR loan to see the cost of skipping income documentation.
- Test whether paying points makes sense by setting Loan A with points (lower rate, higher closing costs) and Loan B without.
The numbers do not lie, but they do depend on the inputs. Use real quotes, not ballpark figures.
Frequently asked questions
Why shouldn't I compare loans by interest rate alone?
Interest rate sets your monthly payment, but total loan cost includes origination fees, discount points, closing costs, and PMI. A loan at 6.75% with $9,000 in closing costs can cost more over 10 years than a loan at 7% with $3,000 in closing costs. Total interest paid plus all upfront fees gives you the real number. Rate is one input, not the answer.
When does a 15-year mortgage beat a 30-year?
A 15-year wins when you plan to hold long term and can absorb the higher payment without straining cash flow. On a $280,000 balance, the 15-year at 6.5% costs roughly $249,000 less in total interest than a 30-year at 7.25%. But the monthly payment jumps from $1,910 to $2,439. If that $529 difference would prevent you from buying your next property, the 30-year is the better tool.
Are adjustable-rate mortgages ever a good choice?
ARMs make sense when your holding period is shorter than the fixed-rate window. A 5/1 ARM at 6.25% vs. a 30-year fixed at 7.25% saves roughly $200/month on a $300,000 loan for the first five years. If you sell or refinance before the adjustment hits, you capture the savings without the rate risk. Investors flipping within 3 to 5 years use ARMs this way regularly.
How do I compare a conventional loan to a DSCR loan?
Conventional loans offer lower rates (often 0.5% to 1% lower) but require personal income documentation and count against your DTI. DSCR loans skip income verification and qualify on the property's rent, but charge higher rates and origination fees. Compare the total cost of each over your expected hold period. For investors maxing out conventional loan slots, DSCR is often the only path to the next property.
When is paying discount points worth it?
Divide the cost of the points by the monthly payment savings to find your breakeven in months. One point on a $300,000 loan costs $3,000 and typically lowers your rate by 0.25%, saving about $50/month. That is a 60-month breakeven. If you plan to hold longer than five years and will not refinance, buying the point pays off. If you might sell or refi sooner, skip it.
What is the opportunity cost of a higher monthly payment?
Every dollar locked into a higher mortgage payment is a dollar you cannot deploy elsewhere. If a 15-year loan costs $500 more per month than a 30-year, that is $6,000 per year not going toward a down payment on another rental. At a 10% return on invested capital, that $6,000 compounds to roughly $95,000 over 10 years. Cheap debt can be more valuable than no debt.
How do closing costs affect which loan is cheaper?
Closing costs are paid upfront and must be included in your total cost comparison. A loan with a 6.75% rate and $12,000 in closing costs vs. 7% with $4,000 in closing costs has an $8,000 head start to overcome through monthly savings. On a $280,000 loan, the lower rate saves about $47/month, taking 170 months (over 14 years) to break even. If you sell before that, the higher-rate loan was cheaper.
Should I compare loans based on APR or total cost?
APR folds origination fees and points into the rate, which helps for quick comparisons. But APR assumes you hold the loan to maturity, which most borrowers do not. A better approach is to calculate total cost over your actual expected hold period: monthly payments times months held, plus closing costs, minus remaining principal. That gives you the real cost of each loan for your specific timeline.