15-Year vs 30-Year Mortgage Comparison Calculator
Compare 15-year vs 30-year mortgage payments, total interest, and savings side by side. See how much you save with a shorter term and decide which is right for you.
Mortgage Comparison Calculator
Compare up to 3 mortgage scenarios side by side. See monthly payments, total interest, total cost, and savings to find the best loan option.
Scenario A
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yrs
Scenario B
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yrs
Scenario C
$
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yrs
Comparison Results
| Metric | Scenario A | Scenario B | Scenario C |
|---|---|---|---|
| Monthly Payment | $1,995.91 | $1,896.20 | $2,654.73 |
| Total Interest | $418,526.69 | $382,633.47 | $177,851.11 |
| Total Cost | $718,526.69 | $682,633.47 | $477,851.11 |
| Savings vs Cheapest | +$240,675.58 | +$204,782.36 | Best |
Lowest Total Cost⧉
Scenario C
$477,851.11
Lowest Payment⧉
Scenario B
$1,896.20
Planning notes, formulas, and examples
About the Mortgage Comparison Calculator
Shopping for a mortgage means weighing multiple offers with different rates, terms, and fee structures. A lower rate does not always mean a cheaper loan — closing costs, points, and term length all affect the true cost. Comparing loans side by side is the clearest way to see those trade-offs in one place.
This Mortgage Comparison Calculator lets you enter up to three loan scenarios and see how they stack up on monthly payment, total interest, and total cost. The unified comparison view highlights the cheapest option and shows exactly how much you save by choosing it.
Whether you are comparing 15-year vs 30-year terms, fixed vs adjustable rates, or offers from different lenders, this calculator reveals the payment and total-cost differences that matter for your budget and planning. The results are most useful when you treat them as a worksheet and then pair them with the lender's Loan Estimate, points details, and closing-cost disclosures.
When This Page Helps
Lender quotes can be confusing — different rate-term-fee combinations make true cost comparison difficult. This calculator standardizes the comparison, showing each scenario on equal footing so you can weigh monthly affordability against total borrowing cost without relying on marketing language from the quote itself.
How to Use the Inputs
- Enter the loan details for Scenario A: loan amount, interest rate, and term.
- Enter loan details for Scenario B with different terms or a different lender's offer.
- Optionally add Scenario C for a third comparison.
- Review the side-by-side results: monthly payment, total interest, and total cost.
- Identify the scenario that best balances monthly affordability with total cost savings.
- Use the savings comparison to quantify the benefit of choosing the cheapest option.
Formula used
Monthly Payment = P × r(1+r)^n / ((1+r)^n − 1). Total Interest = (Payment × n) − P. Total Cost = Payment × n. Savings = max(Total Cost) − min(Total Cost) among the scenarios compared.Example Calculation
Result: A: $1,996/mo ($418K interest) — B: $1,896/mo ($382K interest) — C: $2,633/mo ($174K interest)
Scenario C has the highest monthly payment at $2,633 but the lowest total interest at $174K — saving $244K compared to Scenario A. Scenario B saves $36K versus A with only $100 less per month. The right choice depends on whether you can afford the 15-year payment.
Tips & Best Practices
- Compare multiple lender scenarios using the same base loan amount so the outputs stay comparable.
- Always compare the same loan amount across scenarios so results are directly comparable.
- Factor in closing costs and points when comparing — a lower rate purchased with expensive points may not save money.
- Consider your time horizon — if you plan to move in 5 years, total cost over 5 years matters more than lifetime cost.
- A shorter term always saves interest but requires higher payments — make sure the payment fits your budget comfortably.
- Use this alongside the Mortgage Points Break-Even Calculator to evaluate point-buying offers.
Why Side-by-Side Comparison Matters
A single mortgage quote can look reasonable in isolation. Side-by-side comparison makes it easier to see how rate, term, and closing-cost assumptions move both the required payment and the total borrowing cost.
Building Your Comparison Set
Start with your strongest pre-approval offer as Scenario A. Add a competing lender or a different term as Scenario B. Use Scenario C for a stretch option — perhaps a shorter term or a rate bought down with points. This gives you a baseline, an alternative, and an aspirational target.
Beyond the Numbers
Monthly payment determines your day-to-day budget impact, while total interest determines the long-term cost. The ideal mortgage balances both — affordable monthly payments without unnecessary long-run cost. Your comparison should also consider how long you expect to keep the loan, whether points are involved, and whether other products such as ARMs or HELOCs belong in the decision set.
Sources & Methodology
Last updated:
Methodology
This page runs the standard fixed-rate mortgage payment formula independently for each entered scenario, then compares monthly payment, total interest, and total cost side by side. The "cheapest" flag is based on the lowest total scheduled cost among the valid scenarios, not on APR, closing costs, or program-specific underwriting.
It is a comparison worksheet rather than a full lender quote analysis. If points, lender fees, escrow, or ARM features differ across offers, those items still need to be reviewed in the actual Loan Estimate and closing disclosures.
Sources
- How do I compare two Loan Estimates? (Consumer Financial Protection Bureau) — CFPB guidance on comparing competing mortgage offers using standardized disclosures.
- Loan Estimate (Consumer Financial Protection Bureau) — CFPB explanation of the standardized mortgage disclosure borrowers use to compare rate, payment, and closing-cost structure.
Frequently Asked Questions
Use identical loan amounts and compare monthly payment, total interest, and total cost. If one scenario includes points or higher fees, factor those into the total cost. The APR (annual percentage rate) also helps — it folds fees into an effective rate for easier comparison.
Not necessarily. A lower rate may come with higher upfront costs like discount points or origination fees. Compare the total cost over your expected ownership period. If you plan to sell or refinance within a few years, paying for a lower rate may not break even.
Yes. A shorter term usually raises the payment and lowers total interest. Running both side by side helps you decide whether the payment increase is worth the lower long-run borrowing cost for your situation.
An ARM typically offers a lower initial rate, so it will show lower payments during the fixed period. However, the rate can increase after that period. Compare the ARM's initial payment against fixed-rate options, but remember that ARM costs are uncertain after the fixed period ends.
Three is a good number — it lets you compare your best fixed-rate offer, a shorter-term option, and perhaps an ARM or a different lender's quote. This gives you a well-rounded view of your options without overwhelming the comparison.
This calculator compares the mortgage principal and interest only. Taxes, insurance, and PMI are typically the same regardless of the loan terms, so they do not affect the comparison between scenarios. Use our PITI Calculator for a full cost picture.
More in this topic
Fixed-Rate Mortgage Calculator
Calculate your fixed-rate mortgage payment, total interest, and amortization schedule. Compare 10, 15, 20, 25, and 30-year fixed loan terms.
Mortgage Points Break-Even Calculator
Calculate when buying mortgage points pays off. Compare 0, 1, and 2 point scenarios side by side to find your break-even month and total interest savings.