Finance category
Mortgage, loan, investing, tax, and money calculators.
15-Year vs 30-Year Mortgage Calculator
Compare a 15-year mortgage to a 30-year mortgage at the rates you've been quoted. See the monthly payment difference, total interest savings, and the cash-flow trade-off.
30-year payment
$2,661
Total: $958,036
Interest: $558,036
15-year payment
$3,430
Total: $617,344
Interest: $217,344
Monthly payment difference
+$768
extra cash needed each month
Interest saved on 15
$340,691
over the life of the loan
How to think about it
The 15-year saves enormous interest but requires roughly 29% more cash flow each month. That extra commitment can crowd out retirement contributions, emergency reserves, or down payment savings for the next move.
Many borrowers split the difference: take a 30-year loan and add the difference as principal payment when they can. That keeps the floor flexible if income drops while still attacking principal aggressively.
EveryCalc calculators are designed for fast, practical estimates with transparent inputs and no required account. We use plain formulas, visible assumptions, and related tools so visitors can check the result from more than one angle.
Results are informational only. For financial, tax, legal, medical, construction, or other high-impact decisions, verify the output against primary sources or a qualified professional.
Learn more about our review process on the EveryCalc methodology page.
How this calculator works
What this page estimates
This 15-Year vs 30-Year Mortgage Calculator is built to give a quick, browser-based estimate for 15-year vs 30-year mortgage. Compare a 15-year mortgage to a 30-year mortgage at the rates you've been quoted. See the monthly payment difference, total interest savings, and the cash-flow trade-off. The inputs stay on the page during normal use, and the result should be treated as an estimate for planning, comparison, or education rather than professional advice.
Calculation approach
The calculator applies the standard relationship implied by the inputs, then formats the answer so it can be checked and reused. For finance tools, the most important step is using consistent units, rates, time periods, and assumptions before comparing the result with another calculator or outside quote.
Example workflow
For example, start with a realistic value you already know, change one input at a time, and watch how the answer moves. That makes it easier to tell whether the result is being driven by the main amount, the rate, the time period, or a unit conversion.
Practical checks
- Use current, real-world numbers when the result affects money, health, tax, or legal decisions.
- Run a low, base, and high case when the inputs are estimates.
- Check the related calculators below when the next decision depends on a different assumption.
How to interpret the 15-year vs 30-year mortgage result
Best use
Use the result as a planning number for comparing payments, rates, returns, tax reserves, or cash-flow choices before you request a quote or make a commitment.
Cross-check
Compare the answer with the contract, lender estimate, tax form, brokerage statement, payroll record, or invoice that will control the real-world outcome.
Watch for
Do not rely on a single optimistic rate, return, or fee assumption. Money pages work best when you run low, base, and high cases and keep professional advice separate from the estimate.
This page belongs to the Finance calculator library, so the answer should be read in the context of the decision you are modeling rather than as a universal rule.
Before relying on this 15-year vs 30-year mortgage estimate
Most calculator mistakes come from the inputs, not the arithmetic. Use this short audit before you reuse the answer in a spreadsheet, quote, application, or important conversation.
Confirm source numbers
Match balances, rates, fees, taxes, income, and payment dates against the lender quote, payroll record, tax form, statement, invoice, or contract.
Separate cash flow from total cost
A lower monthly payment can still cost more over time if fees, interest, taxes, or a longer term are hidden in the structure.
Run conservative cases
Test at least one higher-cost or lower-return case before using the output for a purchase, refinance, investment, loan, or tax decision.
Rerun this page when the rate, price, term, fee, tax rule, income, expense, or expected holding period changes.
How to Use
- Enter the same loan amount you'd borrow on either term.
- Enter the rate you've been quoted on the 30-year.
- Enter the rate you've been quoted on the 15-year (typically 0.5–0.75% lower).
- Compare monthly payment, total cost, and interest saved on the 15-year.
- Decide whether the cash-flow flexibility of the 30 outweighs the lifetime interest savings of the 15.
Frequently Asked Questions
Is a 15-year always better mathematically?
Yes for total interest cost — the lower rate plus shorter term usually saves a third or more of the lifetime interest. The trade-off is cash-flow flexibility: the 15-year payment is materially higher and locked in.
Why does a 15-year usually have a lower rate?
Lenders price 15-year loans lower because they take on less duration risk. The shorter average life makes them easier to hedge and securitize at a tighter spread.
What if I want the 15-year savings without the obligation?
Take the 30-year and add the payment difference as extra principal each month. You'll save most of the interest while keeping the floor low if income drops or unexpected expenses hit.
Does the 15-year build equity faster?
Much faster. By year 5 a 15-year loan is roughly 30% paid down vs about 10% on a 30-year. That equity is real money if you sell, refinance, or borrow against it.
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