15-Year vs 30-Year Mortgage Calculator

The 15-year loan is famously cheaper and famously harder to carry. Put both terms on the same home and see the exact trade: how much more per month, how much less interest overall.

1 · Afford 2 · Payment 3 · Schedule 4 · Pay off early 5 · Closing costs 6 · PMI 7 · Refinance 8 · Rates guide

The trade-off in real numbers

On a $340,000 loan, the 30-year at 6.9% costs $2,240 a month and a staggering $466,471 in lifetime interest. The 15-year at 6.0% costs $2,869 a month — $629 more — but only $176,486 in interest. Choosing the 15 saves about $289,985 and has you debt-free in half the time, with equity building several times faster in the early years.

Why the 15-year is not automatically right

Cash-flow risk: the higher payment is mandatory. In a job loss, the 30-year's lower required payment is breathing room you cannot buy later.
Opportunity cost: the $629 difference, invested over 30 years, could rival the interest saved — with market risk attached.
Flexibility strategy: take the 30-year, voluntarily pay it on a 15-year schedule. You get nearly the same result in good times and a safety valve in bad ones — at a slightly higher rate.
Life timing: a 15-year taken at 45 ends at 60 — a powerful retirement plan. At 28 with kids coming, the math may differ.

Run both candidates for your real purchase in the payment calculator, verify the monthly load against your income in the affordability calculator, and if you already hold a 30-year loan, the refinance calculator shows whether switching terms pays after closing costs.

Your next steps

Middle path

30-year paid like a 15

Keep the safety net, get most of the savings.

Your numbers

Payment calculator

Price any term — 10, 15, 20, 30 or 40 years.

Switching?

Refinance calculator

Already own? Check the break-even on a term change.

Related calculators

Mortgage Payment Calculator

Your true monthly payment with taxes, insurance & PMI.

Mortgage Payoff Calculator

Extra payments, lump sums, years and interest saved.

Home Affordability Calculator

How much house your income can really carry.

Refinance Calculator

Break-even and lifetime savings, honestly totaled.

Frequently asked questions

How much do I save with a 15-year mortgage?

On $340,000 borrowed, roughly $290,000 of interest versus a 30-year loan (at typical rate spreads of about 0.9%), plus a payoff 15 years sooner. The saving comes from both the lower rate and the shorter exposure to interest.

Why are 15-year rates lower?

Lenders get their money back sooner, with less time for inflation, rate moves or default — lower risk is priced as a lower rate, typically 0.5–1% below 30-year pricing.

Is a 20-year mortgage a good compromise?

Often, yes: payments sit between the two, interest is far closer to the 15-year outcome, and the rate usually prices near 15-year levels. Our payment calculator lets you set any term.

What if I take the 30-year and pay extra?

You replicate most of the 15-year result with an escape hatch. You will pay slightly more interest than a true 15-year (because of the higher rate) — model your exact extra amount in the payoff calculator.

Which term do most Americans choose?

The 30-year fixed dominates — roughly 90% of purchases — because the lower payment maximizes affordability and flexibility, even though it is the most expensive way to borrow over a full term.

Sources & further reading

Official sources for program rules and consumer rights. Zorvex is not affiliated with these agencies; figures here are estimates for education.