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.

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 instantly 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 tool 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.

Why Use This Mortgage Comparison Calculator?

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 This Calculator

  1. Enter the loan details for Scenario A: loan amount, interest rate, and term.
  2. Enter loan details for Scenario B with different terms or a different lender's offer.
  3. Optionally add Scenario C for a third comparison.
  4. Review the side-by-side results: monthly payment, total interest, and total cost.
  5. Identify the scenario that best balances monthly affordability with total cost savings.
  6. Use the savings comparison to quantify the benefit of choosing the cheapest option.

Formula

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

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

Frequently Asked Questions

How do I compare mortgages fairly?

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.

Is a lower rate always better?

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.

Should I compare 15-year and 30-year loans?

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.

What about adjustable-rate vs fixed-rate?

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.

How many scenarios should I compare?

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.

Does this account for taxes and insurance?

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.

Related Pages