Mortgage Comparison Calculator — Compare Two Home Loans
Enter the amount, rate and term for two mortgages and instantly see which one costs less per month and over the full loan life — useful for comparing lender quotes, fixed vs variable rates, or different loan terms.
%
years
%
years
Loan A costs less per month
- 1
Loan A monthly rate
rA = 6% ÷ 12 ÷ 100 = 0.005 - 2
Loan A monthly payment
300,000 × 0.005 × 6.0226 ÷ (6.0226 − 1) = 1,798.65 - 3
Loan B monthly rate
rB = 6.5% ÷ 12 ÷ 100 = 0.005417 - 4
Loan B monthly payment
300,000 × 0.005417 × 6.9918 ÷ (6.9918 − 1) = 1,896.2 - 5
Monthly saving (A vs B)
|1,798.65 − 1,896.2| = 97.55Loan A costs less per month.
How does this calculator work?
Enter amount, rate and term for two loans; the calculator runs the amortisation formula for each and subtracts to show the monthly saving and total interest difference. A lower monthly payment is not always the better deal — check the total cost too.
Formula
How this is calculated
The calculator applies the standard amortisation formula to each loan independently: it converts the annual rate to a monthly periodic rate (÷ 12 ÷ 100) and the term in years to a number of monthly payments (× 12), then solves for the fixed monthly payment that exactly zeroes the balance over the term. Total paid is that payment times the number of months; total interest is total paid minus the original principal.
The "monthly saving" is simply the difference between the two monthly payments — positive means Loan A is cheaper per month, negative means Loan B is. The interest difference shows the lifetime cost gap, which is often far larger than the monthly payment gap suggests, especially on long-term loans.
Results are principal-and-interest only; they exclude taxes, insurance, PMI and origination fees. Both loans are treated as fully fixed-rate for their entire terms. If you are comparing a fixed rate against an adjustable (ARM) loan, remember that the ARM rate and payment may rise after the initial period.
Frequently asked questions
Not necessarily. A lower monthly payment often comes with a longer term or a higher rate, which can cost significantly more in total interest. Check both the monthly payment and the total lifetime cost before deciding.
Enter the same loan amount and rate but set one term to 15 years and the other to 30 years. The 15-year loan will have a higher monthly payment but far lower total interest — typically saving tens of thousands of dollars.
Yes — for example, a smaller loan with a higher rate versus a larger loan at a lower rate. The calculator shows all figures independently so you can weigh every trade-off.
Also known as
TG we-Calculate Editorial Team. (2026). Mortgage Comparison Calculator — Compare Two Home Loans [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mortgage-comparison-calculator
TG we-Calculate Editorial Team. "Mortgage Comparison Calculator — Compare Two Home Loans." TG we-Calculate. 2026. https://we-calculate.com/calculator/mortgage-comparison-calculator.
TG we-Calculate Editorial Team, "Mortgage Comparison Calculator — Compare Two Home Loans," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mortgage-comparison-calculator
@misc{wecalculate_mortgage_comparison_calculator, title = {Mortgage Comparison Calculator — Compare Two Home Loans}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mortgage-comparison-calculator}}, year = {2026}, note = {TG we-Calculate} }
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