Enter the loan amount and the rate you were quoted for each term. You see both monthly payments, how much interest the 15-year loan saves, and how much equity each loan builds after the number of years you choose.
Last updated:
Loan
$
$
Adds your down payment to equity.
%
%
years
e.g. how long you expect to keep the home.
Optional: invest the difference
% / yr
Enter your values to see the result.
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How to use the 15 vs 30 Year Mortgage Calculator
Enter the loan amount and, if you like, the home value so equity includes your down payment.
Enter the 15-year and 30-year rates you were quoted; 15-year rates are usually lower.
Choose a horizon for the equity comparison, such as the years you expect to stay in the home.
Compare the payments, total interest and equity, and check the side-by-side table.
Tick 'invest the difference' to see whether a 30-year loan plus investing the savings could come out ahead.
How the comparison is calculated
Each loan uses the standard fixed-rate payment formula:
M = P × r ÷ (1 − (1 + r)−n)
with P the loan amount, r the annual rate ÷ 12 ÷ 100, and n = 180 payments for 15 years or 360 for 30 years. Total interest is M × n − P. The balance after k payments is P(1 + r)k − M((1 + r)k − 1) ÷ r, and equity is the loan minus that balance, plus your down payment.
Payment and interest per $100,000 borrowed
Rate
15-yr payment
15-yr total interest
30-yr payment
30-yr total interest
5.0%
$790.79
$42,343
$536.82
$93,256
5.5%
$817.08
$47,075
$567.79
$104,404
6.0%
$843.86
$51,894
$599.55
$115,838
6.5%
$871.11
$56,799
$632.07
$127,544
7.0%
$898.83
$61,789
$665.30
$139,509
7.5%
$927.01
$66,862
$699.21
$151,717
Multiply by your loan size in hundreds of thousands. Remember that the 15-year rate you are offered is usually lower than the 30-year rate, which widens the gap in total interest.
Which term fits you?
Choose 15 years if the higher payment fits comfortably, you want to be debt-free sooner and you value guaranteed interest savings.
Choose 30 years if you need a lower required payment, want room for savings and emergencies, or plan to invest the difference.
How much more is a 15-year mortgage payment than a 30-year?
Usually about 30% to 50% more per month, depending on the two rates. For example, a $350,000 loan at 5.75% for 15 years costs about $2,906 a month, while the same loan at 6.5% for 30 years costs about $2,212.
How much interest does a 15-year mortgage save?
Often more than half of the total interest, because you borrow for half as long and the rate is usually lower. With the default example above, the 15-year loan saves roughly $273,000 in interest.
Why are 15-year mortgage rates lower?
Lenders take less risk over a shorter period and get their money back sooner, so 15-year rates are typically around half a point to three quarters of a point below 30-year rates. The exact spread changes with the market.
Is a 30-year mortgage with extra payments the same as a 15-year?
Not quite. Paying the 15-year amount on a 30-year loan pays it off early too, but you still pay the higher 30-year rate, so the total interest is somewhat higher. The benefit is flexibility: you can drop back to the lower required payment when money is tight.
What does 'invest the difference' assume?
The 30-year borrower invests the monthly payment difference for 15 years. After year 15 the 15-year borrower is debt-free and invests the same amount the 30-year borrower is still paying. Both have the same monthly outflow for 30 years, so the comparison is fair. Returns are not guaranteed and investment gains may be taxed.
How is equity calculated here?
Equity is the principal you have paid off (loan amount minus remaining balance), plus your down payment if you enter the home value. It does not include any change in the home's market value.
Does this include taxes and insurance?
No. Both payments are principal and interest only. Property tax, insurance and PMI are the same for either term, so they do not change the comparison.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.